So if Pierce is unable to play in the season opener, who would start at running back for the Baltimore Ravens? Veteran journeyman Justin Forsett, who hasn't made a start since 2010, could be the one to step up.
Of the Ravens' 24 healthy scratches in the preseason finale, 18 are projected to be starters. The fact that Forsett didn't play as well could suggest the Ravens wanted to keep him healthy for the opener.
The Ravens might trust Forsett to handle the starting role because he's more experienced than rookie Lorenzo Taliaferro and is more familiar with Gary Kubiak's offense after playing in Houston in 2012.
But Forsett wouldn't be asked to carry the entire rushing load. He only had six carries all of last season, and the Ravens would probably split carries with Taliaferro, who led the team with 243 yards rushing this preseason.
A small back, Forsett has impressed the Ravens with his burst. He ran for 69 yards on 16 carries (4.3-yard average) and caught three passes for 37 yards in preseason games. His biggest problem has been holding on to the football (two fumbles this preseason).
None of this speculation will matter if Pierce is able to suit up for the Sept. 7 season opener against the Cincinnati Bengals. Even though Pierce has been banged up throughout his career, he has never missed a game in his two seasons.
There is just no certainty that he'll be healthy enough this time to play.
"Nowadays, with those things, I don't take any stock in that until they tell me that he's back," coach John Harbaugh said Monday. "The concussion thing is hard to predict."