San Francisco 49ers quarterback Jimmy Garoppolo is out for the remainder of the season after breaking his foot early in Sunday's game against the visiting Miami Dolphins.

"Just hearing it is pretty crushing," coach Kyle Shanahan told reporters. "We know what Jimmy's been through, how hard he's worked at this."

The 49ers will turn to rookie Brock Purdy, a seventh-round selection from Iowa State who led San Francisco to a 33-17 victory Sunday in place of Garoppolo.

Garoppolo was 2-of-4 passing for 56 yards on San Francisco's opening drive when he was sacked by a pair of Miami defensive players. The knee of Dolphins linebacker Jaelan Phillips appeared to land on the side of Garoppolo's left foot.

Garoppolo was carted from the sideline to the locker room. He was initially listed as questionable to return, but the Niners downgraded him to out during the second quarter. The 49ers said the injury will require surgery.

The news amplifies quarterback concerns for the 49ers, who lost Trey Lance for the season during San Francisco's second game. Lance subsequently underwent surgery for an ankle injury. Shanahan ruled out the possibility that Lance could be activated sooner than expected.

That leaves Purdy to start at quarterback for a team on an NFL-best five-game winning streak, with a one-game lead in the NFC West as the playoff picture begins to shift into place.

Purdy led San Francisco to a touchdown on his first drive. Purdy hit Kyle Juszczyk on a 3-yard TD pass to cap the 54-yard drive, for his first career scoring pass. He finished the game 25-of-37 passing for 210 yards, two touchdowns and an interception.

The only other quarterback on San Francisco's roster is Jacob Eason, who is on the practice squad.