By Dianna Russini, Matt Barrows and David Lombardi

San Francisco 49ers All-Pro left tackle Trent Williams will end his more than month-long layoff as the 11-time Pro Bowl selection returns to the Bay Area to finalize a deal on Tuesday, league sources said.

Williams’ return comes as the 49ers resume practice Tuesday morning after a four-day break before Labor Day weekend. Shortly after their last session on Thursday, the 49ers finally agreed to a deal with Brandon Aiyuk on a four-year, $120 million extension to end his hold-out amid months of contentious contract talks. Tuesday is expected to be Aiyuk’s first practice with the team since before the Super Bowl in February.

The tone of the Williams talks never reached the level of Aiyuk, who was cleared to request a trade last month. While the 49ers at times seemed exasperated by the Aiyuk situation — “At some point, you have to play,” GM John Lynch said the day before agreeing to the Aiyuk deal — the 49ers never expressed concern about reaching an agreement with Williams.

“I’m optimistic that Trent will be OK,” coach Kyle Shanahan said Wednesday. “I’m sitting here not knowing what day it’s going to be. … When two sides want to make a deal, that’s usually what happens.”

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Williams had three years left on the six-year, $138 million contract he signed in 2021, but there was no guaranteed money left on that contract. He was due a base salary of just over $20 million this season, and most of the money left on that initial deal wasn’t scheduled to expire until the 2026 season, when Williams will be 38.

Because Williams is still the best offensive tackle in football (he’s been a first-team All-Pro the last three seasons), he wanted a pay raise that would at least put him closer to the top of the market, plus some added guarantees.

Williams’ new deal should help mitigate the roughly $4 million in fines he incurred for missing all of training camp and three preseason games. Those fines are non-forgivable under the league’s collective bargaining agreement; fines can only be waived for players still on rookie contracts.

Getting Williams back on the field is a huge boost for the offense. He’s still one of the league’s best pass protectors, and even at 36, he still has the elite movement skills to get down the field on the 49ers’ vaunted wide-zone runs. Even with Williams back, the 49ers are stripped back at offensive tackle, with just two — Jaylon Moore and Colton McKivitz — on the active roster and no one with any NFL game-day experience on the practice squad.

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Williams is more than just physically gifted, though. He’s the most revered player in the locker room. Not only do young offensive linemen flock to him and absorb his every word of advice, but he has the same effect on defensive linemen. He and Nick Bosa regularly have long conversations about the art of pass blocking and pass rushing, especially after games. Williams’ arrival should further boost the team’s confidence and, along with the signing of Aiyuk, change the narrative about what has been a disjointed, distracted summer.

By re-signing Aiyuk, the 49ers appear even more loaded at the skill positions than they were as the NFL’s No. 1 offense in 2023. Quarterback Brock Purdy now has Aiyuk, Deebo Samuel Sr., Christian McCaffrey, George Kittle, Jauan Jennings and rookie Jacob Cowing at his disposal. That group should be able to create enough spacing to allow Purdy to get the ball out quickly, but he’ll still need some semblance of solid protection in front of him — and Williams is the most qualified candidate to provide it on his blind side.

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The 49ers’ biggest offensive weakness heading into Monday’s season opener against the Jets lies in their offensive line’s pass protection. They ranked in the top 20 across the spectrum of pass-blocking metrics last season, and that was with Williams doing a tremendous job of anchoring his position. It’s easy to see disastrous results without him. The three games Williams missed last season were all 49ers losses in which they scored just 17 points each.

Ending Williams’ holdout won’t alleviate all of the 49ers’ concerns. They still appear dangerously thin up the middle, with starter Jake Brendel nursing a patellar tendonitis and the only experienced backup at the position, Jon Feliciano, on the injured list. And none of the other spots along the offensive line protected well last season. Perhaps rookie Dominick Puni will change that at right guard, but that remains to be seen. Williams, on the other hand, is a walking Hall of Famer who’s a first-ballot pick. And that’s worth its weight in gold — as this lucrative renegotiation proves.

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(Photo: Kevin Sabitus/Getty Images)