San Francisco 49ers' Colin Kaepernick (7) is pressured by Houston Texans' Christian Covington (95) during the first half of an NFL preseason football game, Saturday, Aug. 15, 2015, in Houston. (AP Photo/George Bridges)

San Francisco 49ers' Blaine Gabbert (2) hands off to Jarryd Hayne (38) during the first half of an NFL preseason football game against the Houston Texans, Saturday, Aug. 15, 2015, in Houston. (AP Photo/George Bridges)

Houston Texans' Ryan Mallett (15) throws prior to an NFL preseason football game against the San Francisco 49ers, Saturday, Aug. 15, 2015, in Houston. (AP Photo/Patric Schneider)

Houston Texans' Brian Hoyer (7) throws against the San Francisco 49ers during an NFL preseason football game, Saturday, Aug. 15, 2015, in Houston. (AP Photo/Patric Schneider)

Houston Texans' Brian Hoyer (7) hands off to Alfred Blue (28) against the San Francisco 49ers during an NFL preseason football game, Saturday, Aug. 15, 2015, in Houston. (AP Photo/Patric Schneider)

Houston Texans' Cecil Shorts (18) escapes San Francisco 49ers defenders Antoine Bethea (41) and Dontae Johnson (36) as he scores a touchdown during the first half of an NFL preseason football game, Saturday, Aug. 15, 2015, in Houston. (AP Photo/George Bridges)

Houston Texans' Brian Hoyer (7) and DeAndre Hopkins (10) celebrate a two-point conversion against the San Francisco 49ers during the first quarter of an NFL preseason football game, Saturday, Aug. 15, 2015, in Houston. (AP Photo/Patric Schneider)

San Francisco 49ers' Garrett Celek (88) celebrates with teammate Blake Bell (84) after he scored a touchdown against the Houston Texans during the first half of an NFL preseason football game, Saturday, Aug. 15, 2015, in Houston. (AP Photo/George Bridges)

San Francisco 49ers' Colin Kaepernick (7) throws against the San Francisco 49ers during the first half of an NFL preseason football game, Saturday, Aug. 15, 2015, in Houston. (AP Photo/George Bridges)

San Francisco 49ers' Garrett Celek (88) scores a touchdown as Houston Texans' Benardrick McKinney (55) tries to make the stop during the first half of an NFL preseason football game, Saturday, Aug. 15, 2015, in Houston. (AP Photo/George Bridges)

San Francisco 49ers' Colin Kaepernick (7) throws against the San Francisco 49ers during the first half of an NFL preseason football game, Saturday, Aug. 15, 2015, in Houston. (AP Photo/George Bridges)

Houston Texans' Cecil Shorts (18) escapes San Francisco 49ers defenders Antoine Bethea (41) and Dontae Johnson (36) as he scores a touchdown during the first half of an NFL preseason football game, Saturday, Aug. 15, 2015, in Houston. (AP Photo/George Bridges)

Houston Texans' Alfred Blue (28) rushes against the San Francisco 49ers during the first half of an NFL preseason football game, Saturday, Aug. 15, 2015, in Houston. (AP Photo/George Bridges)

Houston Texans' Brian Hoyer (7) and DeAndre Hopkins (10) celebrate a two-point conversion against the San Francisco 49ers during the first quarter of an NFL preseason football game, Saturday, Aug. 15, 2015, in Houston. (AP Photo/Patric Schneider)

San Francisco 49ers' Garrett Celek (88) celebrates with teammate Blake Bell (84) after he scored a touchdown against the Houston Texans during the first half of an NFL preseason football game, Saturday, Aug. 15, 2015, in Houston. (AP Photo/George Bridges)

San Francisco 49ers' Garrett Celek (88) celebrates with teammates after he scored a touchdown against the Houston Texans during the first half of an NFL preseason football game, Saturday, Aug. 15, 2015, in Houston. (AP Photo/George Bridges)

Houston Texans' Ryan Mallett (15) calls a play during the first half of an NFL preseason football game against the San Francisco 49ers, Saturday, Aug. 15, 2015, in Houston. (AP Photo/George Bridges)

Houston Texans' Jaelen Strong (11) catches a pass for a touchdown as San Francisco 49ers' Marcus Cromartie (47) defends him during the second half of an NFL preseason football game, Saturday, Aug. 15, 2015, in Houston. (AP Photo/George Bridges)

San Francisco 49ers' Kenneth Acker (20) breaks up a pass intended for Houston Texans' Chandler Worthy (6) during the second half of an NFL preseason football game, Saturday, Aug. 15, 2015, in Houston. (AP Photo/Patric Schneider)

Aug. 15, 2015 - Houston, Texas, U.S - San Francisco 49ers cornerback Tramaine Brock (26) breaks up a pass in the end zone intended for Houston Texans wide receiver Alan Bonner (16) during the 1st half of an NFL preseason game between the Houston Texans and the San Francisco 49ers at NRG Stadium in Houston, TX on August 15th, 2015. (Cal Sport Media via AP Images)

Aug. 15, 2015 - Houston, Texas, U.S - Houston Texans quarterback Ryan Mallett (15) passes the ball during the 1st half of an NFL preseason game between the Houston Texans and the San Francisco 49ers at NRG Stadium in Houston, TX on August 15th, 2015. (Cal Sport Media via AP Images)

San Francisco 49ers' Dontae Johnson (36) loses control to the ball after he made a catch over Houston Texans' Khari Lee (86) during the second half of an NFL preseason football game, Saturday, Aug. 15, 2015, in Houston. The play was ruled a catch. (AP Photo/George Bridges)

Houston Texans' Chris Polk (22) is dropped by San Francisco 49ers' Rory Anderson (48) during the second half of an NFL preseason football game, Saturday, Aug. 15, 2015, in Houston. (AP Photo/Patric Schneider)

Aug. 15, 2015 - Houston, Texas, U.S - Houston Texans wide receiver Chandler Worthy (6) receives a kickoff during the 1st half of an NFL preseason game between the Houston Texans and the San Francisco 49ers at NRG Stadium in Houston, TX on August 15th, 2015. (Cal Sport Media via AP Images)

Houston Texans' Tom Savage (3) is pulled down by San Francisco 49ers' Eli Harold, left, during the second half of an NFL preseason football game, Saturday, Aug. 15, 2015, in Houston. (AP Photo/George Bridges)

Houston Texans' Alfred Blue (28) rushes against the San Francisco 49ers during the first half of an NFL preseason football game, Saturday, Aug. 15, 2015, in Houston. (AP Photo/George Bridges)

San Francisco 49ers' Blaine Gabbert (2) is tripped up by Houston Texans' Tevita Finau (94) during the first half of an NFL preseason football game, Saturday, Aug. 15, 2015, in Houston. (AP Photo/George Bridges)

Houston Texans' Ryan Mallett (15) looks to throw against the San Francisco 49ers during the first half of an NFL preseason football game, Saturday, Aug. 15, 2015, in Houston. (AP Photo/George Bridges)

Houston Texans' Alfred Blue (28) rushes against the San Francisco 49ers during the first half of an NFL preseason football game, Saturday, Aug. 15, 2015, in Houston. (AP Photo/George Bridges)

San Francisco 49ers' Jarryd Hayne (38) is stopped during the first half of an NFL preseason football game against the Houston Texans Saturday, Aug. 15, 2015, in Houston. (AP Photo/George Bridges)