49ers coach Jim Harbaugh said following Sunday's loss at Denver that center Daniel Kilgore suffered a broken ankle in the third quarter when an opponent inadvertently landed on the side of his lower left leg, per The Sacramento Bee.
Kilgore was replaced by rookie Dillon Farrell, who then left the game because of a sprained ankle. Though, Harbaugh indicated Farrell's injury was not serious and will be in the mix to replace Kilgore. Fellow rookie Marcus Martin could also be in the mix to start at center.