Nick Mullens replaced hobbled starter Jimmy Garoppolo as the 49ers' quarterback at the start of the second half Sunday against the New York Jets.
The 49ers ruled Garoppolo out for the remainder of the game at the start of the third quarter, as he sustained an ankle injury after Jets defensive lineman Quinnen Williams sacked him early in the first quarter. The QB limped noticeably for the rest of the half.
Garoppolo was ailing, but his performance didn't suffer, as he completed 14 of 16 passes for 131 yards and two touchdowns -- both to tight end Jordan Reed. The 49ers led the Jets 21-3 at halftime.
Before Sunday, Mullens hadn't thrown a pass in a regular-season game since Dec. 30, 2018. Mullens replaced C.J. Beathard as the 49ers' starting QB after Garoppolo tore his ACL during the 2018 season, going 3-5 and posting a 90.3 passer rating.
RELATED: Sherman live-tweets Mostert's unreal 80-yard TD vs. Jets
Garoppolo was the fourth 49er to be ruled out during Sunday's game, after running back Raheem Mostert and defensive linemen Nick Bosa and Solomon Thomas all left with knee injuries. Mostert didn't take the field in the second half, and Bosa and Thomas were carted off in the first quarter.
The 49ers already were without multiple key players coming into the game. Wide receiver Deebo Samuel (foot) and cornerback Richard Sherman (calf) are on injured reserve, and tight end George Kittle (knee) and defensive end Dee Ford (neck) also didn't play Sunday.