Redskins coach Jay Gruden said Peterson would get an MRI on Tuesday to determine the severity of the injury.
While the team is awaiting official word, Peterson was quick to provide his own medical update.
"It's not going to keep me out," the 33-year-old Peterson said. "I came back into the game. It was just a situation where it was sore.
"I just thank God it wasn't worse."
Peterson sustained the injury following a 24-yard completion late in the first half and was on the field for two snaps in the second half. He said he knew something was "seriously wrong" when he was injured.
"I just popped it back in, braced it up at halftime and got back in there," Peterson said.
Peterson finished Monday's game with four carries for six yards and two catches for 36 more.
A 2012 NFL Most Valuable Player and seven-time Pro Bowl selection, Peterson has rushed for 242 yards on 60 carries with three touchdowns this season.