49ers running back Isaac Guerendo tore a pectoral muscle about a month ago while lifting weights, coach Kyle Shanahan said.
Shanahan said Guerendo could be ready by the end of training camp.
The 49ers signed running backs Jordan Mims and Jermar Jefferson on Thursday to help fill in while Guerendo is out.
Guerendo has an injury history, with hamstring, groin, foot sprain, ankle and shoulder injuries since joining the 49ers as a fourth-round pick in 2024.
He did not play an offensive snap in 2025, but did see action on 173 special teams in 14 games.
The 49ers have made an addition to their offensive backfield.
The agents for running back Jordan Mims announced that their client has agreed to a deal with the NFC West club. Mims appeared in one game for the Titans in 2025.
Mims initially signed with the Bills after going undrafted in 2023 and moved on to the Saints to make his regular season debut. He played two games as a rookie and 11 games the next season. He has 20 carries for 71 yards and 12 catches for 71 yards for his career.
Christian McCaffrey is the lead back for the 49ers. Jordan James, Isaac Guerendo, Patrick Taylor, Sincere McCormick, and third-round pick Kaelon Black are the other backs.
UPDATE 4:35 p.m. ET: The NFL’s daily transaction wire shows that the 49ers also signed running back Jermar Jefferson. They waived McCormick and placed defensive back Darrick Forrest on injured reserve.
The Commanders have been seen as a landing spot for wide receiver Brandon Aiyuk since it became clear he would not be playing for the 49ers anymore, but Aiyuk remains on the roster for San Francisco.
Aiyuk has no guaranteed money left on his contract after the 49ers voided the remaining guarantees last year, so there’s no particular time pressure for the team to release him and the Commanders have not shown any willingness to give up assets to trade for him. One of the reasons the Commanders have been seen as a suitor is the presence of Aiyuk’s college teammate Jayden Daniels, but the quarterback said he doesn’t have any insight into how things will play out.
“I don’t know, I don’t have a sense on it,” Daniels said, via multiple reporters. “That is my brother and we have a personal relationship. His football future, that’s out of my control.”
Aiyuk has not played a game since Week 7 of the 2024 season and the absence of any sense of when things might be resolved with the 49ers makes it hard to expect to see him on the field for the Commanders or anyone else in the near future.
49ers tight end George Kittle suffered a torn Achilles in January during San Francisco’s postseason win over Philadelphia.
He’s trying hard to return in time for Week 1. But the 49ers’ season-opening trip to Australia to face the Rams on Thursday of that week (which will be Friday in Melbourne) adds a layer of complication.
In a recent interview with Front Office Sports, Kittle noted that playing in that matchup is his goal.
“I was told it’s not a crazy goal,” Kittle said, via David Bonilla of 49erswebzone.com. “And so, as long as I keep on the right path and everything goes the right way, hey, I got a chance.
“As a 15-hour flight and a game like four days before a normal opening day, that might make it a little bit difficult — sure, but who doesn’t like a challenge? So, no, I’ve got a chance, like I said, so just going to keep my head down, keep grinding every single day.”
Head coach Kyle Shanahan has been quite clear about his frustrations with starting 2026 so far from home. Kittle didn’t go nearly as far as Shanahan with his comments, but he did admit that he’d prefer to start 2026 stateside.
“At least, if we started the season off at home, and I didn’t have to hop on a plane for 15 hours, it might be different,” Kittle said. “But I think it just depends on how I’m feeling, if I’m cleared to go. If I’m cleared, hey, I’ll be there, and I’ll be on the field. And if they’re like, ‘Hey, it’s close,’ it’ll be a game-time decision. So, we’ll see.
“Everybody keeps telling me I won’t be back until Week 6, 7, or 8, and I’ll be like, ‘You guys believe whatever you want to believe.’ My goal is to be back there as early as possible.”
Kittle, 32, is entering his 10th pro season. He caught 57 passes for 628 yards with seven touchdowns in 11 games for San Francisco last year.
49ers quarterback Mac Jones is set to make a little more money in 2026.
According to multiple reports, Jones and the 49ers have agreed on a revised contract for the coming season. The reworked deal includes a $300,000 roster bonus for the backup to Brock Purdy.
Jones is now due to make $3.55 million in total compensation for the final year of his contract with the NFC West team. There are another $2.25 million in incentives available as well.
Jones started eight games for the 49ers while Purdy was sidelined with a toe injury during the 2025 season. The Niners would prefer to turn to him less often this year, but the team’s 5-3 record with Jones shows why they value having him on hand.
