San Francisco running back Brandon Jacobs has injured his left knee in the first quarter of Saturday night's game against the Houston Texans.
Jacobs was injured when he was hit by Kareem Jackson at the end of an 8-yard run late in the first quarter. Jacobs remained on the turf for several minutes while trainers talked with him. He was helped to his feet and hopped off the field on his right leg before being placed on a cart and taken to the locker room.
There was no immediate word on the severity of his injury.
Jacobs joined the 49ers in the offseason after seven seasons with the New York Giants.