49ers injury news: Dominick Puni, Mac Jones suffered knee sprains, other updates

San Francisco 49ers head coach Kyle Shanahan provided several important injury updates following Tuesday's practice, the team's first on-field work of the week as it prepares for its preseason finale against the Los Angeles Chargers.

Shanahan confirmed that rookie guard Dominick Puni suffered a knee sprain during last week's preseason matchup with the Las Vegas Raiders.

"He's going to be out for a few weeks," Shanahan said.

Shanahan admitted that there is a concern that Puni, the team's starting right guard, might not be available for the start of the regular season.

"There's a concern, but I know he's got a chance to, also," Shanahan told reporters.

Quarterback Mac Jones also sustained a knee sprain. However, his timeline seems shorter, with Shanahan noting that Jones will sit out Saturday's game against the Chargers but should be ready for Week 1.

"He should be fine for Week 1," Shanahan noted. "We just know he can't go this week."

The news was more concerning for rookie running back Corey Kiner, who suffered a high-ankle sprain against the Raiders. Shanahan explained that the severity of the injury could sideline him for at least a month, possibly longer.

"It was a high ankle sprain, and it was a pretty bad one," Shanahan said. "When it's not a bad one, I still consider that a month, so I would expect maybe a little longer."

There's a possibility Kiner could begin the season on injured reserve.

Meanwhile, fellow running back Patrick Taylor Jr. underwent surgery for a fractured shoulder and will miss the entire 2025 NFL season. The 49ers officially placed him on injured reserve ahead of Tuesday's practice.

Shanahan also revealed that defensive end Yetur Gross-Matos, who is recovering from a knee injury, could start the season on the physically unable to perform (PUP) list.

"That hasn't been coming as fast as we want," Shanahan admitted. "We've still got two more weeks here that we're hoping for, but that'll be one of our big decisions."

The outlook is more optimistic for rookie cornerback Upton Stout, who is working back from a calf strain. Shanahan said he does not anticipate Stout missing Week 1 but cautioned that calf injuries can linger.

"I hope close," Shanahan said when asked about Stout's timeline to return. "He had a good workout yesterday. Today was a recovery day. Anytime you're dealing with a calf, calves can linger and add to other things. ... I'd like to say sooner than later. I haven't been concerned about Week 1 or anything like that, but hopefully, it'll be sooner than later."

Wide receiver Jauan Jennings is in a similar situation with a calf injury. Like Stout, his progress will depend on how quickly he can return to practice.

"Hopefully, he can get his health back, so he can get out there and start practicing, just running routes, doing things like that," Shanahan said. "Same thing for Upton. Not many people can get through that stuff without practicing."

Additionally, Shanahan said rookie defensive end Mykel Williams was close to returning to practice this week.

"We're still looking at him as day-to-day, but definitely hoping for him by next week," Shanahan said.