Houston Texans running back Arian Foster led the NFL with 1,616 rushing in 2010. Quite impressive for a second-year back who was undrafted out of Tennessee in 2009 and didn't enter the league until November of that year. Even more impressive? Foster did that on one good knee. As he recently told The Sporting News:
Like a painter lacking a full palette, Foster says he played the 2010 season with a torn meniscus in his knee, telling nobody until the season was over because he didn’t want to lose his job.
He did have surgery in February, but at the time it was talked about as a minor injury. That's some amazing subterfuge to pull off for nearly a year. But check out that entire article linked above for more on how interesting of a person Foster is. It should come as no surprise then that he did this.
Foster won't need to worry about losing his job this year. Steve Slaton may ultimately be traded, Derrick Ward isn't a threat to unseat him and Ben Tate, returning from injury, is more than likely to be the main kick returner.
Just imagine what Foster will do this season on two good knees. He could help lead the Texans to a playoff berth after all these years.