Mike Garafolo of FOX Sports 1 reports Buccaneers running back Doug Martin suffered what's believed to be a torn labrum in his left shoulder and his season may be over.
Rick Stroud of the Tampa Times confirmed that Martin suffered a torn labrum but said the Bucs would not place him on IR immediately because they hope he can return in 2013.
Ian Rapoport of NFL.com first reported Martin's injury was serious and he could miss several weeks.
Martin's shoulder was injured when hit by Falcons safety William Moore while attempting to catch a pass in the third quarter Sunday. Rookie Mike James replaced Martin and finished with 14 carries for 45 yards.
After the game, Martin said X-rays on his shoulder looked "fine" and that it wasn't separated.
"We're still evaluating what it is,'' said Martin, who added that he's "not sure yet'' if he would play in Thursday night's game against Carolina.
"Just have to hope for the best.''