SANTA CLARA, Calif. – After four practices this week, the San Francisco 49ers welcome back left tackle Trent Williams and receiver Brandon Aiyuk for Monday night’s season opener against the New York Jets.

For Williams and Aiyuk, who both resolved their contract issues in time to begin practice with the Niners on Tuesday, the question remains how many snaps they will be able to play after missing nearly all of training camp and the preseason.

The answer, it seems, could be different for each player. According to coach Kyle Shanahan on Saturday, Williams will likely take on more of his full, normal workload, while Aiyuk will slightly reduce the number of snaps he normally plays.

Since Williams plays offensive tackle, the Niners are less likely to want to swap him out of the rotation with backup Jaylon Moore unless it is absolutely necessary.

Shanahan said Williams has returned in good form and has improved in each of the four practices the team has held this week. Still, that’s not a lot of time to then compete for an entire game, meaning Williams will be closely watched by offensive line coach Chris Foerster throughout the game.

“I would have liked to have him (play the whole game), but you have to watch it,” Shanahan said. “We have to talk to him. I haven’t done that a lot with a tackle. O-linemen are different when it comes to rotation … but it’s also weird to see Trent just sitting next to us on the sideline. That’s something we’re going to keep an eye on all game and he’ll be honest with us about how he feels.”

The Niners will make a roster change by Monday afternoon to make room for Williams, who was placed on the reserve/non-reporting list after waiting 40 days for a revised contract. Williams was able to practice this week due to a roster exemption. Shanahan said the corresponding roster change has not yet been made.

Williams signed a revised contract on Tuesday worth $82.66 million over three years with $48 million guaranteed. Foerster said Williams will be ready to play after a few days of practice.

“Trent is Trent,” Foerster said. “He’s still Trent. He goes out there and I think like always, I think we’ve talked about how you prepare guys for the game, there’s that back and forth when you’re going full speed against someone who’s pushing you. Yesterday he struggled a little bit, but today he seemed a lot better and tomorrow he’ll keep pushing. We’ll see how it goes.”

Aiyuk, who signed a four-year, $120 million contract extension on Aug. 30, has been with the team as a “hold-in” throughout training camp and the preseason, allowing him to attend meetings but not practice. Shanahan said Aiyuk is also in good shape and looks his usual self, but will likely play a little less due to the pressures at his position. Aiyuk typically plays most of the game, as he played 82% of San Francisco’s offensive snaps in 16 games last season.

“I don’t know how much he’s going to play yet,” Shanahan said. “He usually plays most of the game. I’d probably be surprised if he played that much, but he’s in good shape. He’s had a really good week. His pain hasn’t been too bad. After every practice he’s really pushed himself, done a few extra things afterward and he looks good and ready to go.”

Aiyuk and quarterback Brock Purdy have even tried to make more time to work together. Last weekend, they organized a one-on-one throwing practice to get their heads in tune. Purdy said the extra time has been beneficial.

“It was huge,” Purdy said. “Just him and I out on the field and we got back to our fundamentals, like routes and everything. …That was a good day for me to get back in tune, see how he moves and feel it out again. This week at practice, we kind of picked up where we left off.”

While Aiyuk and Williams will play, running back Christian McCaffrey was officially questionable due to calf and Achilles injuries with the 49ers. McCaffrey participated in limited practice all week, but said Friday he has no doubts he will play against the Jets and is confident he can handle his usual workload as the team’s primary running back.

Shanahan said Saturday that McCaffrey’s injury was unrelated to the one he suffered in Week 17 of last season against the Washington Commanders, but added, “I think it’s similar.”

Jordan Mason would be the starting running back for any snaps McCaffrey cannot take.

Safety Talanoa Hufanga, still recovering from a torn ACL in his right knee, is listed as questionable after returning to practice in recent weeks. The injury occurred on Nov. 20 of last year and Hufanga spent most of training camp on the physically unable to perform list.

Although Hufanga is unlikely to play against the Jets, his return is imminent.

“I don’t think it’s necessarily too early,” Shanahan said. “I think he’s made a great impression, so we’re trying to be as safe as possible with him. Let’s be smart with him. We haven’t ruled him out for emergency or anything, which means if it was needed, he would be available.”

Also on the injured list are defensive end Yetur Gross-Matos (knee) and linebacker Dee Winters (ankle). Like McCaffrey, guard Aaron Banks (pinky finger) is also questionable.