Dallas Cowboys quarterback Tony Romo (9) throws a pass in the first half of an NFL preseason football game against the Miami Dolphins, Friday, Aug. 19, 2016, in Arlington, Texas. (AP Photo/Michael Ainsworth)

Dallas Cowboys quarterback Tony Romo (9) hands off the ball to linebacker James Morris in the first half of an NFL preseason football game, Friday, Aug. 19, 2016, in Arlington, Texas. (AP Photo/Michael Ainsworth)

Dallas Cowboys running back Darius Jackson (34) finds running room against the Miami Dolphins in an NFL preseason football game, Friday, Aug. 19, 2016, in Arlington, Texas. (AP Photo/Ron Jenkins)

Dallas Cowboys wide receiver Dez Bryant (88) reaches out to catch a pass in front of Miami Dolphins defensive back Byron Maxwell in the first half of an NFL preseason football game, Friday, Aug. 19, 2016, in Arlington, Texas. (AP Photo/Michael Ainsworth)

Miami Dolphins quarterback Ryan Tannehill (17) hands off the ball to running back Jay Ajayi (23) in the first half of an NFL preseason football game against the Dallas Cowboys, Friday, Aug. 19, 2016, in Arlington, Texas. (AP Photo/Ron Jenkins)

Miami Dolphins defensive tackle Ndamukong Suh (93) and Chris Jones (52) pressure Dallas Cowboys quarterback Tony Romo (9) during the first half of an NFL preseason football game, Friday, Aug. 19, 2016, in Arlington, Texas. (AP Photo/Ron Jenkins)

Miami Dolphins quarterback Ryan Tannehill (17) is pressured out of the pocket by Dallas Cowboys defensive end Jack Crawford (58) during the first half of an NFL preseason football game, Friday, Aug. 19, 2016, in Arlington, Texas. (AP Photo/Ron Jenkins)

Dallas Cowboys' Anthony Hitchens (59) and Morris Claiborne, rear, tackle Miami Dolphins wide receiver Jarvis Landry after a short catch and run in the first half of an NFL preseason football game, Friday, Aug. 19, 2016, in Arlington, Texas. (AP Photo/Ron Jenkins)

Dallas Cowboys defensive end Demarcus Lawrence (90) pressures Miami Dolphins quarterback Ryan Tannehill (17) in the first half of an NFL preseason football game, Friday, Aug. 19, 2016, in Arlington, Texas. (AP Photo/Michael Ainsworth)

Dallas Cowboys' Tony Romo, left, and head coach Jason Garrett celebrate a touchdown against the Miami Dolphins in the first half of an NFL preseason football game, Friday, Aug. 19, 2016, in Arlington, Texas. (AP Photo/Ron Jenkins)

Dallas Cowboys running back Alfred Morris (46) escapes a tackle-attempt by Miami Dolphins' Andre Branch on his way to the end zone for a touchdown on a running play in the first half of an NFL preseason football game, Friday, Aug. 19, 2016, in Arlington, Texas. (AP Photo/Ron Jenkins)

Miami Dolphins wide receiver Kenny Stills (10) celebrates after catching a pass for a touchdown in front of Dallas Cowboys' Damien Wilson (57) and Barry Church, right, in the first half of an NFL preseason football game, Friday, Aug. 19, 2016, in Arlington, Texas. (AP Photo/Ron Jenkins)

Dallas Cowboys' Brice Butler and Dak Prescott, right, celebrate Prescott's touchdown in the first half of an NFL preseason football game against the Miami Dolphins, Friday, Aug. 19, 2016, in Arlington, Texas. (AP Photo/Ron Jenkins)

Dallas Cowboys quarterback Dak Prescott (4) runs past Miami Dolphins' Terrence Fede (78) and Spencer Paysinger (42) into the end zone for a touchdown in the first half of an NFL preseason football game, Friday, Aug. 19, 2016, in Arlington, Texas. (AP Photo/Ron Jenkins)

Miami Dolphins running back Jay Ajayi (23) runs the ball fighting off pressure from Dallas Cowboys middle linebacker Anthony Hitchens (59) in the first half of an NFL preseason football game, Friday, Aug. 19, 2016, in Arlington, Texas. (AP Photo/Michael Ainsworth)

Dallas Cowboys defensive back Jeremiah McKinnon, left, is unable to stop Miami Dolphins wide receiver Kenny Stills (10) from making a catch for a touchdown in the end zone in the first half of an NFL preseason football game, Friday, Aug. 19, 2016, in Arlington, Texas. (AP Photo/Michael Ainsworth)

Miami Dolphins quarterback Ryan Tannehill (17) keeps the ball for a run as Dallas Cowboys' Ryan Russell (99) pursues in the first half of an NFL preseason football game, Friday, Aug. 19, 2016, in Arlington, Texas. (AP Photo/Michael Ainsworth)

Miami Dolphins quarterback Matt Moore (8) is helped off the field by staff after suffering an unknown injury in the first half of an NFL preseason football game against the Dallas Cowboys on Friday, Aug. 19, 2016, in Arlington, Texas. (AP Photo/Michael Ainsworth)

Miami Dolphins quarterback Matt Moore (8) is helped by staff after suffering an unknown injury in the first half of an NFL preseason football game against the Dallas Cowboys, Friday, Aug. 19, 2016, in Arlington, Texas. (AP Photo/Michael Ainsworth)

Miami Dolphins defensive tackle Chris Jones (52) applies pressure as Dallas Cowboys' Dak Prescott (4) jumps to throw a pass in the first half of an NFL preseason football game, Friday, Aug. 19, 2016, in Arlington, Texas. (AP Photo/Michael Ainsworth)

Dallas Cowboys' Cedric Thornton (92) runs back a recovered fumble in the first half of an NFL preseason football game against the Miami Dolphins, Friday, Aug. 19, 2016, in Arlington, Texas. (AP Photo/Ron Jenkins)

Miami Dolphins quarterback Brandon Doughty (6) fumbles the ball after being hit by Dallas Cowboys' Shaneil Jenkins in the first half of an NFL preseason football game, Friday, Aug. 19, 2016, in Arlington, Texas. The Cowboys recovered the fumble. (AP Photo/Ron Jenkins)

Dallas Cowboys wide receiver Brice Butler (19) reaches to make a catch in front of Miami Dolphins' Bobby McCain (28) in the second half of an NFL preseason football game, Friday, Aug. 19, 2016, in Arlington, Texas. (AP Photo/Michael Ainsworth)

Dallas Cowboys running back Darius Jackson (34) fights for extra yardage against Miami Dolphins free safety Walt Aikens, right, in the second half of an NFL preseason football game, Friday, Aug. 19, 2016, in Arlington, Texas. (AP Photo/Ron Jenkins)

Dallas Cowboys quarterback Dak Prescott, center top, fights to get over the line of scrimmage scoring a touchdown as Miami Dolphins' Julius Warmsley (73) and Mike Hull (45) defend in the second half of an NFL preseason football game, Friday, Aug. 19, 2016, in Arlington, Texas. (AP Photo/Ron Jenkins)

Miami Dolphins tight end Thomas Duarte (83) attempts to stop Dallas Cowboys tight end Austin Traylor (86) who runs the ball after recovering a blocked punt in the second half of an NFL preseason football game, Friday, Aug. 19, 2016, in Arlington, Texas. (AP Photo/Michael Ainsworth)

Miami Dolphins head coach Adam Gase, left, stands on the sideline with quarterback Ryan Tannehill in the second half of an NFL preseason football game against the Dallas Cowboys on Friday, Aug. 19, 2016, in Arlington, Texas. (AP Photo/Michael Ainsworth)

Miami Dolphins quarterback Ryan Tannehill, left, and Dallas Cowboys quarterback Tony Romo, right, greet each other after an NFL preseason football game, Friday, Aug. 19, 2016, in Arlington, Texas. (AP Photo/Michael Ainsworth)