New England Patriots' Tim Tebow throws a pass during a joint workout with the Philadelphia Eagles at NFL football training camp, Philadelphia, Wednesday, Aug. 7, 2013. (AP Photo/Matt Rourke)

Philadelphia Eagles head coach Chip Kelly walks on the field during a joint workout with the New England Patriots at NFL football training camp in Philadelphia, Wednesday, Aug. 7, 2013. (AP Photo/Matt Rourke)

Minnesota Vikings rookie defensive tackle Sharrif Floyd (95), a first-round draft pick, lines up for one-on-one drill during NFL football training camp, Wednesday, Aug. 7, 2013 in Mankato, Minn. (AP Photo/Jim Mone)

A giant Viking hovers in the background as the defensive players walk through drills during the Minnesota Vikings NFL football training camp, Wednesday, Aug. 7, 2013 in Mankato, Minn. (AP Photo/Jim Mone)

Carolina Panthers wide receiver Taulib Ikharo (83) reaches for a pass as D.J. Moore (20) defends during NFL football training camp practice in Spartanburg, S.C., Wednesday, Aug. 7, 2013. (AP Photo/Chuck Burton)

Tennessee Titans wide receiver Rashad Ross tries to catch three footballs during a drill at NFL football training camp on Monday, Aug. 5, 2013, in Nashville, Tenn. (AP Photo/Mark Humphrey)

Cincinnati Bengals quarterback Andy Dalton, right, runs a drill with fellow quarterbacks Josh Johnson, center, and John Skelton during a joint practice with the Atlanta Falcons at NFL football training camp at the Falcons' practice facility, Monday, Aug. 5, 2013, in Flowery Branch, Ga. (AP Photo/David Goldman)

Indianapolis Colts wide receiver Nathan Palmer (10) leaps to attempt a catch during practice at the NFL team's football training camp Monday, Aug. 5, 2013, in Anderson, Ind. (AP Photo/Darron Cummings)

A parachuter descends for landing on the football field during the singing of the national anthem at the sixth annual ?Kia Motors Friday Night Lights? at Bobby Gruhn Field at City Park Stadium, Friday, Aug. 2, 2013, in Gainesville, Ga. (AP Photo/Jaime Henry-White)

Tennessee Titans inside linebacker Moise Fokou (53) defends against tight end Taylor Thompson (84) during NFL football training camp on Monday, Aug. 5, 2013, in Nashville, Tenn. The assumption has been that the Titans' starting middle linebacker job will go to Colin McCarthy, a defensive captain a year ago. But Fokou, one of Tennessee's free agent signees, has worked with the first-team defense all but one day. Now McCarthy's dealing with yet another injury, giving Fokou more of a chance to win the job. (AP Photo/Mark Humphrey)

Indianapolis Colts head coach Chuck Pagano watches as players stretch during practice at the NFL team's football training camp Monday, Aug. 5, 2013, in Anderson, Ind. (AP Photo/Darron Cummings)

Arizona Cardinals' Lorenzo Alexander fights off the blocking dummy as he goes after the ball carrier at NFL football training camp practice on Monday, Aug. 5, 2013, in Glendale, Ariz. (AP Photo/Ross D. Franklin)

Cincinnati Bengals head coach Marvin Lewis, left, talks with Atlanta Falcons head coach Mike Smith, right, during a joint practice at NFL football training camp at the Falcons' practice facility, Monday, Aug. 5, 2013, in Flowery Branch, Ga. (AP Photo/David Goldman)

Arizona Cardinals' Carson Palmer gives signals during passing drills at NFL football training camp practice on Monday, Aug. 5, 2013, in Glendale, Ariz. (AP Photo/Ross D. Franklin)

Philadelphia Eagles' Michael Vick throws a pass at the NFL football team's training camp in Philadelphia, Monday, Aug. 5, 2013. (AP Photo/Matt Rourke)

Arizona Cardinals' Larry Fitzgerald runs drills during an NFL football training camp, Friday, Aug. 2, 2013, in Glendale, Ariz. (AP Photo/Matt York)

Washington Redskins quarterback Robert Griffin III (10) salutes the crowd during the afternoon session at NFL football training camp in Richmond, Va., Friday, Aug. 2, 2013. (AP Photo/Steve Helber)

Oakland Raiders fullback Jeremy Stewart carries the ball with a stretch band attached during NFL football training camp Friday, Aug. 2, 2013, in Napa, Calif. (AP Photo/Eric Risberg)

Atlanta Falcons quarterback Matt Ryan, right, hands off to teammate Steven Jackson during a joint practice with the Cincinnati Bengals at NFL football training camp at the Falcons' practice facility, Monday, Aug. 5, 2013, in Flowery Branch, Ga. (AP Photo/David Goldman)

Washington Redskins quarterback Robert Griffin III, left, looks for a receiver along with teammate Rex Grossman, right, during the afternoon practice at the NFL football team's training camp in Richmond,Va. Monday, Aug. 5, 2013. (AP Photo/Steve Helber)

Arizona Cardinals' Robby Toma makes a catch at NFL football training camp practice on Monday, Aug. 5, 2013, in Glendale, Ariz. (AP Photo/Ross D. Franklin)

Carolina Panthers' DeAngelo Williams, left, runs past Greg Hardy, right, during an NFL football training camp practice in Spartanburg, S.C., Friday, Aug. 2, 2013. (AP Photo/Chuck Burton)

Jacksonville Jaguars running back Jordan Todman (30) breaks through the defense during NFL football training camp Friday Aug. 2, 2013 in Jacksonville, Fla.(AP Photo/ Kelly Jordan)

A young Kansas City Chiefs fans plays with a toy while sitting in the bleachers during NFL football training camp in St. Joseph, Mo., Friday, Aug. 2, 2013. (AP Photo/Orlin Wagner)

Washington Redskins running back Alfred Morris (46) hauls in a pass in front of inside linebacker Perry Riley (56) during the afternoon session at NFL football training camp in Richmond, Va., Friday, Aug. 2, 2013. (AP Photo/Steve Helber)

CORRECTS TO AUG. 2-St. Louis Rams linebacker Will Witherspoon, right, and safety Rodney McLeod take part in a drill during training camp at the NFL football team's practice facility Friday, Aug. 2, 2013, in St. Louis. (AP Photo/Jeff Roberson)

Denver Broncos quarterback Peyton Manning warms up during NFL football training camp in Englewood, Colo., on Friday, Aug. 2, 2013. (AP Photo/David Zalubowski)

Denver Broncos tight end Julius Thomas, right, pulls in pass in front of strong safety Duke Ihenacho during NFL football training camp in Englewood, Colo., on Friday, Aug. 2, 2013. (AP Photo/David Zalubowski)

Cleveland Browns quarterback Brandon Weeden scrambles during NFL football training camp at the team's practice facility in Berea, Ohio Friday, Aug. 2, 2013. (AP Photo/David Richard)

Tennessee Titans wide receiver Rashad Ross catches a pass as he runs a drill around trash cans during NFL football training camp on Friday, Aug. 2, 2013, in Nashville, Tenn. (AP Photo/Mark Humphrey)

Arizona Cardinals quarterback Carson Palmer throws during an NFL football training camp, Friday, Aug. 2, 2013, in Glendale, Ariz. (AP Photo/Matt York)

Kansas City Chiefs tight end Anthony Fasano (80) catches a pass during NFL football training camp in St. Joseph, Mo., Friday, Aug. 2, 2013. (AP Photo/Orlin Wagner)

Tennessee Titans players watch teammates play during NFL football training camp on Wednesday, July 31, 2013, in Nashville, Tenn. (AP Photo/Mark Humphrey)

Cleveland Browns wide receiver Naaman Roosevelt catches a pass during practice at training camp at the NFL football team's facility in Berea, Ohio Friday, August 2, 2013. (AP Photo/David Richard)

Seattle Seahawks running back Christine Michael, right, keeps his footing on the rain-slick grass, Friday, Aug. 2, 2013, during NFL football training camp in Renton, Wash. (AP Photo/Ted S. Warren)

Seattle Seahawks cornerback Richard Sherman, left, begins to take off the jersey that belongs to injured wide receiver Sidney Rice, right, after Sherman wore it as a joke during NFL football training camp Friday, Aug. 2, 2013, in Renton, Wash. (AP Photo/Ted S. Warren)

Buffalo Bills' C.J. Spiller carries the ball during their NFL football training camp in Pittsford, N.Y., Wednesday, July 31, 2013. (AP Photo/Bill Wippert)

Oakland Raiders cornerback D.J. Hayden goes up for a pass during NFL football training camp Saturday, July 27, 2013, in Napa, Calif. (AP Photo/Eric Risberg)

San Francisco 49ers defensive end Tony Jerod-Eddie (63) goes through drills under instruction from coach Jim Tomsula during NFL football training camp on Thursday, Aug. 1, 2013, in Santa Clara, Calif. (AP Photo/Marcio Jose Sanchez)

San Francisco 49ers quarterback Colin Kaepernick warms up during NFL football training camp on Thursday, Aug. 1, 2013, in Santa Clara, Calif. (AP Photo/Marcio Jose Sanchez)

Carolina Panthers' Garry Williams (65) battles Kawann Short (68) during practice at NFL football training camp in Spartanburg, S.C., Thursday, Aug. 1, 2013. (AP Photo/Chuck Burton)

Oakland Raiders defensive back Charles Woodson looks on during their NFL football training camp on Friday, July 26, 2013, in Napa, CA. (Tony Gonzales/Raiders.com)

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San Diego Chargers quarterback Philip Rivers, center, calls a play during NFL football training camp Thursday, Aug. 1, 2013, in San Diego. (AP Photo/Denis Poroy)

Carolina Panthers' Luke Kuechly runs a drill during an NFL football training camp practice in Spartanburg, S.C., Thursday, Aug. 1, 2013. (AP Photo/Chuck Burton)

Detroit Lions quarterback Matthew Stafford throws at the teams NFL football practice facility in Allen Park, Mich., Thursday, Aug. 1, 2013. (AP Photo/Paul Sancya)

Pittsburgh Steelers quarterback Ben Roethlisberger passes at practice during NFL football training camp 2in Latrobe, Pa. on Thursday, Aug. 1, 2013 . (AP Photo/Keith Srakocic)

Chicago Bears tight end Martellus Bennett, left, catches a ball against safety Major Wright during NFL football training camp Thursday, Aug. 1, 2013, in Bourbonnais, Ill. (AP Photo/Nam Y. Huh)

Atlanta Falcons wide receiver Julio Jones runs through a drill during training camp at the NFL football team's practice facility, Thursday, Aug. 1, 2013, in Flowery Branch, Ga. (AP Photo/David Goldman)

Washington Redskins nose tackle Chris Neild, right, tries to handle a punt as outside linebacker Rob Jackson, left, watches during the morning practice at the NFL football teams training camp in Richmond, Va., Wednesday, July 31, 2013. (AP Photo/Steve Helber)

Seattle Seahawks running back Marshawn Lynch catches a pass during during NFL football training camp, Thursday, Aug. 1, 2013, in Renton, Wash. (AP Photo/Ted S. Warren)

Chicago Bears quarterback coach Matt Cavanaugh, right, talks with quarterback Jay Cutler during NFL football training camp on Thursday, Aug. 1, 2013, in Bourbonnais, Ill. (AP Photo/Nam Y. Huh)

Atlanta Falcons' Marcus Jackson, second from right, runs through a drill with teammates during training camp at the NFL football team's practice facility on Thursday, Aug. 1, 2013, in Flowery Branch, Ga. (AP Photo/David Goldman)

Seattle Seahawks quarterback Russell Wilson (3) passes during during NFL football training camp, Thursday, Aug. 1, 2013, in Renton, Wash. (AP Photo/Ted S. Warren)

Some members of the Pittsburgh Steelers' offensive line do stretching exercises in front of the scoreboard at St. Vincent College before practice during NFL football training camp in Latrobe, Pa., on Thursday, Aug. 1, 2013. (AP Photo/Keith Srakocic)

Atlanta Falcons' Steven Jackson catches a pass during NFL football training camp at the team's practice facility, Thursday, Aug. 1, 2013, in Flowery Branch, Ga. (AP Photo/David Goldman)

Carolina Panthers' Steve Smith laughs as he hears thunder during practice at NFL football training camp in Spartanburg, S.C., Thursday, Aug. 1, 2013. (AP Photo/Chuck Burton)

Washington Redskins quarterback Robert Griffin III (10) runs down a line of outstretched hands of fans during the afternoon practice at the NFL football teams training camp in Richmond, Va., Wednesday, July 31, 2013. (AP Photo/Steve Helber)

Indianapolis Colts linebacker Bjoern Werner works against a blocking dummy during practice at the NFL team's football training camp in Anderson, Ind., Wednesday, July 31, 2013. (AP Photo/Michael Conroy)

Philadelphia Eagles' Michael Vick, center, throws a pass near Eagles coach Chip Kelly, left, at the NFL football team's training camp in Philadelphia, Wednesday, July 31, 2013. (AP Photo/Matt Rourke)

Buffalo Bills' Kip Edwards (39) breaks up a pass intended for Marcus Easley (81) during their NFL football training camp in Pittsford, N.Y., Tuesday, July 30, 2013. (AP Photo/Bill Wippert)

Detroit Lions defensive backs drill at the teams NFL football practice facility in Allen Park, Mich., Tuesday, July 30, 2013. (AP Photo/Paul Sancya)

New Orleans Saints quarterback Drew Brees (9) signs autographs for Shaan Jindal, 11, left, and Slade Jindal, 9, sons of Louisiana Gov. Bobby Jindal, during their NFL football training camp in Metairie, La., Tuesday, July 30, 2013. (AP Photo/Gerald Herbert)

Buffalo Bills quarterback EJ Manuel (3) runs a play during their NFL football training camp in Pittsford, N.Y., Tuesday, July 30, 2013. (AP Photo/Bill Wippert)

Tampa Bay Buccaneers quarterback Josh Freeman throws a pass during the NFL football team's training camp Saturday, July 27, 2013, in Tampa, Fla. (AP Photo/Chris O'Meara)

Detroit Lions running back Reggie Bush, right, runs a drill at the teams NFL football practice facility in Allen Park, Mich., Monday, July 29, 2013. (AP Photo/Paul Sancya)

Denver Broncos rookie safety Ross Rasner carries pads in from NFL football training camp, Monday, July 29, 2013, in Englewood, Colo. (AP Photo/Jack Dempsey)

Chicago Bears wide receiver Brandon Marshall, left, runs with a ball against cornerback Charles Tillman during NFL football training camp Friday, July 26, 2013, at Olivet Nazarene University in Bourbonnais, Ill. (AP Photo/Nam Y. Huh)

Minnesota Vikings running back Adrian Peterson catches the ball during NFL football training camp, Friday, July 26, 2013, in Mankato, Minn. (AP Photo/Charlie Neibergall)

Minnesota Vikings quarterback Christian Ponder throws a pass during NFL football training camp, Monday, July 29, 2013, in Mankato, Minn. (AP Photo/Charlie Neibergall)

Pittsburgh Steelers defensive end Brett Keisel drives an off-road dump truck up the driveway towards the team dormitories as he arrives for the start of their NFL football training camp at the team training facility in Latrobe, Pa., on Friday, July 26, 2013. (AP Photo/Keith Srakocic)

Atlanta Falcons' Rashad Evans, right, makes a catch in front of teammate Terrence Johnson during training camp at the NFL football team's practice facility on Friday, July 26, 2013, in Flowery Branch, Ga. (AP Photo/David Goldman)

St. Louis Rams defensive end Chris Long, left, and tackle Rodger Saffold take part in a drill during NFL football training camp at the team's practice facility Friday, July 26, 2013, in St. Louis. (AP Photo/Jeff Roberson)

Minnesota Vikings wide receiver Adam Thielen, right, catches a pass over cornerback Josh Robinson during NFL football training camp on Friday, July 26, 2013, in Mankato, Minn. (AP Photo/Charlie Neibergall)

Kansas City Chiefs coach Andy Reid, left, stands behind quarterback Alex Smith (11) during NFL football training camp in St. Joseph, Mo., Friday, July 26, 2013. (AP Photo/Orlin Wagner)

Atlanta Falcons' Tony Gonzalez warms up during training camp at the NFL football team's practice facility on Friday, July 26, 2013, in Flowery Branch, Ga. Gonzalez never liked training camp, and this will be his last one. He has returned to the Atlanta Falcons at age 37 in hopes of playing in his first Super Bowl. (AP Photo/David Goldman)

New York Jets coach Rex Ryan, left, poses with defensive assistant Jeff Weeks at NFL football training camp on Friday, July 26, 2013, in Cortland, N.Y. (AP Photo/Bill Kostroun)

New York Giants defensive end Justin Tuck runs during NFL football training camp in East Rutherford, N.J., Friday, July 26, 2013. (AP Photo/Julio Cortez)

Denver Broncos linebacker coach Richard Smith goes over a play during NFL football training camp, Friday, July 26, 2013, in Englewood, Colo. (AP Photo/Jack Dempsey)

Chicago Bears wide receiver Terrence Toliver catches a ball during NFL football training camp Friday, July 26, 2013, at Olivet Nazarene University in Bourbonnais, Ill. (AP Photo/Nam Y. Huh)

Detroit Lions receiver Calvin Johnson runs through drills during NFL football training camp in Allen Park, Mich., Friday, July 26, 2013. (AP Photo/Carlos Osorio)

Baltimore Ravens defensive tackles Brandon Williams, from front left, and Haloti Ngata, run a drill in front of offensive linesman Jordan Devey and defensive tackle Chris Canty during NFL football training camp at the team's practice facility in Owings Mills, Md., Friday, July 26, 2013. (AP Photo/Patrick Semansky)

New York Jets quarterback Mark Sanchez, right, hands the ball off to running back Bilal Powell at their NFL football training camp Friday, July 26, 2013, in Cortland, N.Y. (AP Photo/Bill Kostroun)

Green Bay Packers' Aaron Rodgers runs a drill during NFL football training camp Friday, July 26, 2013, in Green Bay, Wis. (AP Photo/Morry Gash)

Jacksonville Jaguars running back Maurice Jones-Drew (32) walks off the field with his two-year-old son, Madden, after a practices session at NFL football training camp, Friday, July 26, 2013, in Jacksonville, Fla. (AP Photo/John Raoux)

Tennessee Titans running back Chris Johnson talks with reporters during NFL football training camp on Friday, July 26, 2013, in Nashville, Tenn. (AP Photo/Mark Humphrey)

Houston Texans' Nick Mondek (69) and Ryan Harris (68) jog off one practice field to another during NFL football training camp Friday, July 26, 2013, in Houston. (AP Photo/Pat Sullivan)

Green Bay Packers' Jordy Nelson rides a bike to NFL football training camp Friday, July 26, 2013, in Green Bay, Wis. (AP Photo/Morry Gash)

Houston Texans' Ed Reed gestures as he walks across the field during NFL football training camp Friday, July 26, 2013, in Houston. (AP Photo/Pat Sullivan)

New England Patriots wide receiver Josh Boyce, right, runs a drill during NFL football training camp in Foxborough, Mass., Friday, July 26, 2013.(AP Photo/Charles Krupa)

Houston Texans' Arian Foster makes a catch during NFL football training camp Friday, July 26, 2013, in Houston. (AP Photo/Pat Sullivan)

Tampa Bay Buccaneers cornerback Darrelle Revis retrieves a ball during NFL football training camp Thursday, July 25, 2013, in Tampa, Fla. (AP Photo/Mike Carlson)

Denver Broncos quarterback Peyton Manning throws during the opening session of NFL football training camp Thursday, July 25, 2013, in Englewood, Colo. (AP Photo/Jack Dempsey)

Kansas City Chiefs linebacker Mike Catapano works out during NFL football training camp in St. Joseph, Mo., Thursday, July 25, 2013. (AP Photo/Orlin Wagner)

Washington Redskins quarterback Robert Griffin III, left, hands the ball off to Alfred Morris, right, during NFL football training camp in Richmond, Va. Thursday, July 25, 2013. (AP Photo/Steve Helber)

Miami Dolphins wide receiver Brian Hartline (82) runs drills during an NFL football practice, Wednesday, July 24, 2013, in Davie, Fla. (AP Photo/Lynne Sladky)

Dallas Cowboys quarterback Tony Romo (9) looks to pass at NFL football training camp on Sunday, July 21, 2013, in Oxnard, Calif. (AP Photo/Jason Redmond)

Kansas City Chiefs running backs work out during NFL football training camp in St. Joseph, Mo., Tuesday, July 23, 2013. (AP Photo/Orlin Wagner)

Green Bay Packers' Ryan Pickett during NFL football training camp Saturday, July 27, 2013, in Green Bay, Wis. (AP Photo/Morry Gash)

Indianapolis Colts wide receiver Reggie Wayne walks away from an IU Health LifeLine helicopter after he arrived with Riley Hospital patient Matt Sercer, 20, from Plainfield, Ind., as he reported for the NFL team's football training camp in Anderson, Ind., Saturday, July 27, 2013. (AP Photo/Michael Conroy)

New England Patriots quarterback Tom Brady (12) runs sprints with the team during NFL football training camp in Foxborough, Mass. on Saturday, July 27, 2013. (AP Photo/Michael Dwyer)

Atlanta Falcons center Peter Konz (66) leads the offensive line in a drill during NFL football training camp in Flowery Branch, Ga., Saturday, July 27, 2013. Tackle Sam Baker (72) and guard Garrett Reynolds (75) also participate. (AP Photo/John Bazemore)

Baltimore Ravens fullback Vonta Leach, left, and running back Ray Rice walk on the field during NFL football training camp in Owings Mills, Md., Wednesday, July 31, 2013. Leach signed a two-year contract Monday with the defending Super Bowl champions after failing to find a proper suitor in the free-agent market. (AP Photo/Patrick Semansky)

Jacksonville Jaguars cornerback Dwayne Gratz, right, breaks up a pass intended for wide receiver Ace Sanders, left, during NFL football training camp, Monday, July 29, 2013, in Jacksonville, Fla. (AP Photo/John Raoux)

Pittsburgh Steelers outside linebacker Jason Worilds (93) performs shadow drills with the other linebackers during NFL football training camp in Latrobe, Pa., on Wednesday, July 31, 2013. (AP Photo/Keith Srakocic)

Indianapolis Colts wide receiver Reggie Wayne reaches out as he attempts a catch during practice at the NFL team's football training camp in Anderson, Ind., Wednesday, July 31, 2013. (AP Photo/Michael Conroy)

San Diego Chargers wide receiver Keenan Allen, the team's third round draft choice this year, hauls in a pass into the end zone during a scrimmage at the team's practice at their training camp in San Diego, Sunday, July 28, 2013. (AP Photo/Lenny Ignelzi)

San Diego Chargers wide receiver Malcom Floyd runs a route while being covered by cornerback Derek Cox during the team's practice at their training camp in San Diego, Sunday, July 28, 2013. (AP Photo/Lenny Ignelzi)

Cincinnati Bengals running back BenJarvus Green-Ellis runs the ball during practice at the NFL football team's training camp, Wednesday, July 31, 2013, in Cincinnati. (AP Photo/Al Behrman)

A member of the Kansas City Chiefs training staff moves equipment during NFL football training camp in St. Joseph, Mo., Thursday, Aug. 1, 2013. (AP Photo/Orlin Wagner)