San Francisco 49ers quarterback Colin Kaepernick runs for a touchdown against the Minnesota Vikings during the second quarter of an NFL preseason football game in San Francisco, Friday, Aug. 10, 2012. (AP Photo/Paul Sakuma)

San Francisco 49ers wide receiver Brett Swain (18) catches a touchdown pass next to Minnesota Vikings defensive back Chris Carr (25) during the first quarter of an NFL preseason football game in San Francisco, Friday, Aug. 10, 2012. (AP Photo/Paul Sakuma)

San Francisco 49ers running back Brandon Jacobs carries against the Minnesota Vikings during the first quarter of an NFL preseason football game in San Francisco, Friday, Aug. 10, 2012. (AP Photo/Ben Margot)

Minnesota Vikings coach Leslie Frazier watches from the sideline during the first quarter of an NFL preseason football game against the San Francisco 49ers in San Francisco, Friday, Aug. 10, 2012. (AP Photo/Ben Margot)

San Francisco 49ers wide receiver Brett Swain, right, celebrates with offensive tackle Joe Staley (74) and running back Rock Cartwright (28) after catching a touchdown pass against the Minnesota Vikings during the first quarter of an NFL preseason football game in San Francisco, Friday, Aug. 10, 2012. (AP Photo/Paul Sakuma)

Minnesota Vikings quarterback Christian Ponder (7) slides as San Francisco 49ers linebacker Patrick Willis (52) converges during the first half of an NFL preseason football game in San Francisco, Friday, Aug. 10, 2012. (AP Photo/Ben Margot)

Minnesota Vikings nose tackle Fred Evans (90) celebrates with defensive end Christian Ballard (99) after sacking San Francisco 49ers quarterback Colin Kaepernick during the second quarter of an NFL preseason football game in San Francisco, Friday, Aug. 10, 2012. (AP Photo/Ben Margot)

Minnesota Vikings quarterback Joe Webb (14) is sacked by San Francisco 49ers linebacker Parys Haralson, rear, and defensive tackle Ricky Jean Francois (95) during the second quarter of an NFL preseason football game in San Francisco, Friday, Aug. 10, 2012. (AP Photo/Ben Margot)

San Francisco 49ers quarterback Colin Kaepernick smiles on the sideline after scoring on a touchdown run against the Minnesota Vikings during the second quarter of an NFL preseason football game in San Francisco, Friday, Aug. 10, 2012. (AP Photo/Paul Sakuma)

San Francisco 49ers running back Rock Cartwright (28) carries as Minnesota Vikings linebacker Tyrone McKenzie (58) tries to bring him down, while defensive end D'Aundre Reed (91) gives chase during the first half of an NFL preseason football game in San Francisco, Friday, Aug. 10, 2012. (AP Photo/Paul Sakuma)

Minnesota Vikings nose tackle Fred Evans, left, sacks San Francisco 49ers quarterback Colin Kaepernick during the second quarter of an NFL preseason football game in San Francisco, Friday, Aug. 10, 2012. (AP Photo/Ben Margot)

San Francisco 49ers coach Jim Harbaugh watches from the sideline during the second half of an NFL preseason football game against the Minnesota Vikings in San Francisco, Friday, Aug. 10, 2012. (AP Photo/Paul Sakuma)