San Diego Chargers quarterback Philip Rivers prepares to release a pass during the first half of the Chargers' NFL football game against the Arizona Cardinals in San Diego on Sunday, Dec. 31, 2006. Rivers threw two touchdown passes but left the game with a injured ankle. (AP Photo/Lenny Ignelzi)

San Diego Chargers running back LaDainian Tomlinson (21) breaks a tackle by Cincinnati Bengals safety Madieu Williams, left, on his way to a two-yard touchdown in the fourth quarter of their NFL football game, Sunday, Nov. 12, 2006, in Cincinnati. Tomlinson rushed for four touchdowns and 104 yards in the Chargers 49-41 win. (AP Photo/David Kohl)

Tampa Bay Buccaneers linebacker Derrick Brooks is chased by Washington Redskins wide receiver Darnerien McCants and tackle Jon Jansen as he returns an interception 44 yards for a touchdown Sunday, Oct. 12, 2003, in Landover, Md. Tampa Bay beat Washington 35-13. (AP Photo/Evan Vucci)

Buffalo Bills Thurman Thomas (34) escapes from New York Jets Leonard Marshall, left, and Kyle Clifton during their game on Sunday, Oct. 24, 1993 at Giants Stadium in East Rutherford, New Jersey. Thomas had 27 carries for 117 yards as the Bills beat the Jets 19-10. (AP Photo/Mark Lennihan)

Miami Dolphins' quarterback Dan Marino is seen in action, 1985. (Associated Press)

Hall of Fame wide receiver James Lofton (80) of the Green Bay Packers makes the catch before being stopped by Rams linebacker Jim Youngblood (53) during the Packers 35-23 loss to the Los Angeles Rams on September 20, 1981 at the Anaheim Stadium in Anaheim. (National Football League)

Minnesota Vikings running back Chuck Foreman (44) carries the football during the Vikings 24-7 loss to the Miami Dolphins in Super Bowl VIII on January 13, 1974 at Rice Stadium in Houston,Texas. (National Football League)

Terry Bradshaw, football player for the Pittsburgh Steelers, is shown, Jan. 20, 1980 in Pasadena, Calif., during the Super Bowl. (Associated Press)

Bubba Smith, defensive end of Baltimore Colts, stops Carl Garrett, (30) running back of Boston Patriots, with a two-yard gain as the Colts scored a 27-3 victory in Baltimore, Oct. 26, 1970. A tough Baltimore defense held the Patriots to 45 yards on the ground and minus-65 yards in the air with four pass interceptions. (Associated Press)

Hall of Fame running back Jim Taylor of the Green Bay Packers heads up the field on a run during the Packers 27-17 loss to the Los Angeles Rams on October 25, 1964 at Milwaukee County Stadium in Milwaukee, Wisconsin. (National Football League)