St. Louis Rams rookie safety T.J. McDonald was carted off the field with 10 minutes left in the third quarter after suffering an injury to his right leg.
On a first down carry from San Francisco 49ers running back Frank Gore, McDonald was attempting to make a play on Gore. As he was falling to the ground, his right leg whipped and collided with teammate Gerald Rivers. McDonald also lost his helmet on the play and was in very visible pain while laying on the turf.
The training staff put his right leg in an air cast before loading him onto a cart and taking him off the field.
McDonald will not return to the game. He was replaced by Matt Giordano.
UPDATE 11:32 p.m. ET: According to Ian Rapoport of the NFL Network, McDonald suffered a fractured leg on the play.