Marshall Faulk 's decision was easy after spending last year working for the NFL Network: At 34, his body is more suited for a television studio than for the rigors of playing running back. After sitting out last season because of a knee injury, Faulk officially announced his retirement. He's ninth on the NFL's career rushing list, 33 yards behind Jim Brown, who at one time was the standard for the position. Faulk is fourth in combined yards from scrimmage with 19,154 yards and his 6,875 yards receiving are the most ever among running backs. "Just being around the game last year, I realized how much I love it," Faulk said. "But my health is everything. And I didn't want to return if I couldn't get through a full season. It all came together when a close friend asked me 'How many 34-year-old running backs are there?'" Faulk starred at San Diego State, where he rushed for 386 yards and seven touchdowns in his first game, and led the nation in rushing as a freshman.