SANTA CLARA, Calif. -- Trey Lance's season is over less than five full quarters into his first year as the San Francisco 49ers' starting quarterback.

Lance broke his right ankle with 2:20 to go in the first quarter of Sunday's 27-7 win against the Seattle Seahawks. Backup Jimmy Garoppolo replaced Lance and finished the game, as he reassumes starting duties with Lance now out.

Coach Kyle Shanahan confirmed the injury and said Lance is scheduled for season-ending surgery Monday morning.

"It's always tough, especially when it's a big one like that," Shanahan said. "You feel for someone so bad. It's sad but you don't have time to sit there and think about it. You've got to get right back to the game, and the guys did a real good job of that. I'm really happy about the win, but it's a little somber once you get in the locker room."

When the Niners returned to the locker room after the victory, Shanahan struck a similar tone with his team, telling it to be proud of the win but to take a moment to keep Lance in its thoughts.

Lance's injury came on a second-down run on a zone-read play in which he had the option to hand it to receiver Ray-Ray McCloud or keep it himself and run it up the middle. Lance chose the latter and, after gaining 2 yards, collided with Seahawks linebacker Cody Barton. Lance fell awkwardly and his right ankle seemed to fold underneath him.

Initially, Lance appeared poised to get back up, and center Jake Brendel tried to help him, but he quickly went back down and the cart was brought out to help him off the field. Lance's right leg was also put in an air cast as teammates streamed onto the field to offer encouragement.

Most of the 49ers and Shanahan knew instantly that Lance had suffered a serious injury and expected the worst as the second-year quarterback was ruled out for the game just minutes later.

"You can tell when injuries like that happen right away and they bring the stabilizing stuff out and the cart out," tackle Mike McGlinchey said. "It's a haunting moment for anybody that's on the football field, and it can happen to anybody. Unfortunately, it happened to him on that play and we're praying for him and hope he just gets better."

Lance was 2-of-3 passing for 30 yards and had three carries for 13 yards before the injury.

After leading the Niners in rushing attempts (13) and yards (54) in a Week 1 loss to the Bears, Lance spoke at length Wednesday about the differences between college and the NFL and the need to protect himself when running, noting that he was no longer "bigger, faster and stronger than pretty much everyone else."

In 2021, Lance started only two games, and he suffered a left knee sprain in a loss to the Arizona Cardinals in his first start. He also dealt with a broken finger suffered in a preseason game. That small sample of playing and getting hurt was a significant factor in the Niners' decision to bring back Garoppolo.

It also brought questions for Shanahan after Sunday's game about Lance's usage in the run game as it relates to keeping him healthy.

"Any time a guy gets hurt I wish I could call [a different play]," Shanahan said. "But that's something we were going to do and something we were going to continue to do. It's a football play we believe in and something that gives him a chance to be successful in this league."

After the game, Garoppolo called stepping back into the starting role something of a "full-circle" moment. Despite not taking any reps with the starting offense since January and not participating in practice or meetings through all of training camp while he rehabbed his surgically repaired right shoulder, Garoppolo said getting back under center for the Niners was "like riding a bike."

Garoppolo looked healthy and comfortable right away, completing 8 of 11 passes for 106 yards and a touchdown in the first half after replacing Lance. He finished 13-of-21 for 154 yards and a touchdown, adding a TD run to cap San Francisco's scoring.

"It was more just about getting the shoulder ready," Garoppolo said. "Mentally, I knew the scheme. Some of the new plays took a little while to learn, there's always some new wrinkles in the offense, but for the most part it was just, 'Once my shoulder was good, I was ready to roll.'"

And now, Garoppolo will have to be prepared for the rest of the season as he steps back into the role he has held for most of the past five years, with rookie Brock Purdy as his backup. In the process, Garoppolo has a chance to earn back a large chunk of the money he gave up in the reworked contract he did with the Niners on Aug. 29. That new deal reduced his base salary from $24 million to $6.5 million (fully guaranteed) with incentives built in for playing time and team success that could earn him up to $16 million.

In fact, Garoppolo earned an extra $350,000 on Sunday, $250,000 for playing at least 25% of the snaps and $100,000 for the win. But Garoppolo's mind wasn't so much on the win or the incentives as it was on his injured teammate Sunday. Garoppolo went through a lengthy rehab of his own after suffering a torn left ACL against the Kansas City Chiefs on Sept. 23, 2018.

"It felt good to be back out there," Garoppolo said. "I felt terrible for Trey. I've been on that side in this league. It's tough. Every person has their share of injuries. But that sucks for him and I feel bad for him, but he's our brother and we'll pick him up."