Peterson said the injury happened in the second quarter of the loss to the Saints. Peterson appeared to grab his right shoulder after being tackled at the end of a 24-yard reception up the left sideline. Chris Thompson and Kapri Bibbs took over as the Washington running backs for the remainder of the game.
Peterson will have an MRI on his injured shoulder on Tuesday. He had four carries for six yards and caught two passes for 36 yards before exiting the game.