The San Francisco 49ers are worried that Jimmy Garoppolo, the team’s emerging star at quarterback, has torn his left anterior cruciate ligament, which would end his season. And the questions will immediately swirl as to whether this could open the door for a return to the N.F.L. by Colin Kaepernick.
The 26-year-old Garoppolo was injured at the tail end of a 13-yard run as he tried to rally his team in the fourth quarter. His left foot stepped out of bounds on the play, with his knee buckling awkwardly, before he endured hard contact to his upper body on a hit by Steve Nelson.