San Diego Chargers quarterback Philip Rivers throws a pass during warm ups before an NFL preseason football game against the San Francisco 49ers, Thursday, Aug. 29, 2013, in San Diego. (AP Photo/Denis Poroy)

San Francisco 49ers head coach Jim Harbaugh gestures before an NFL preseason football game against the San Diego Chargers, Thursday, Aug. 29, 2013, in San Diego. (AP Photo/Denis Poroy)

San Diego Chargers defensive back Marcus Cromartie warms up before an NFL preseason football game against the San Francisco 49ers, Thursday, Aug. 29, 2013, in San Diego. (AP Photo/Denis Poroy)

San Francisco 49ers quarterback Colin Kaepernick throws a pass during warm ups before an NFL preseason football game against the San Diego Chargers, Thursday, Aug. 29, 2013, in San Diego. (AP Photo/Denis Poroy)

San Francisco 49ers quarterback Colin Kaepernick, left, throws a pass in front of teammate quarterback Colt McCoy, right, during warm ups before an NFL preseason football game against the San Diego Chargers, Thursday, Aug. 29, 2013, in San Diego. (AP Photo/Denis Poroy)

San Francisco 49ers head coach Jim Harbaugh, left, tosses a football to quarterback Colin Kaepernick during warm ups before an NFL preseason football game against the San Diego Chargers, Thursday, Aug. 29, 2013, in San Diego. (AP Photo/Denis Poroy)

San Francisco 49ers quarterback Colin Kaepernick throws a pass during warm ups before an NFL preseason football game against the San Diego Chargers, Thursday, Aug. 29, 2013, in San Diego. (AP Photo/Denis Poroy)

San Diego Chargers quarterback Philip Rivers throws a pass during warm ups before an NFL preseason football game against the San Francisco 49ers, Thursday, Aug. 29, 2013, in San Diego. (AP Photo/Denis Poroy)

San Diego Chargers inside linebacker Manti Te'o laughs as he makes a catch before an NFL preseason football game against the San Francisco 49ers Thursday, Aug. 29, 2013, in San Diego. (AP Photo/Denis Poroy)