RENTON, Wash. -- Seattle Seahawks center Connor Williams has unexpectedly decided to retire at 27 years old, walking away from the team with eight games left this season.

Coach Mike Macdonald said Friday the seven-year veteran made the decision earlier this week for "personal reasons." The only other detail he provided on Williams' reasoning was that it's not because of any issues with his surgically-repaired knee. Macdonald is under the impression the decision is final, saying he doesn't think there's a chance Williams changes his mind.

"I don't believe so," Macdonald said. "We're honoring his wishes and we'll keep all those reasons and conversations private for obvious reasons and wish him the best."

Macdonald said Olu Oluwatimi will take over at center and the Seahawks probably will make a roster move Saturday.

Williams had started all nine games for Seattle (4-5) this season and played every offensive snap after signing with the team during training camp. He was at practice Monday when the Seahawks returned from their bye to begin preparations for their game Sunday against the San Francisco 49ers, but he was then was listed as a nonparticipant in practice the past three days with a not-injury-related/personal designation.

Macdonald wouldn't specify when he started to have an inkling that Williams was thinking of retiring. Asked when Williams told him of his decision, Macdonald said, "It's been a process throughout the week."

"You start getting into timetables and all that, I'd rather keep it private with ... Connor and the things that he's working through," he said. "But it was this week."

Williams' departure deals a major blow to Seattle's embattled offensive line, which ranks 27th in pass block win rate and has also struggled to create movement in the run game. Injuries have forced the Seahawks to use three different right tackles in Abraham Lucas' absence. They've also rotated at right guard, where Anthony Bradford and rookie third-round pick Christian Haynes have struggled to the point that Seattle considered the possibility of moving Williams there.

Lucas will make his 2024 debut Sunday, though he might not play every snap in his first game after knee surgery in January. Lucas was a full participant the past two days of practice.

"We're anticipating to see him right now in a pretty significant manner," Macdonald said. "We're still on a progression here, so the amount of reps that he's going to get, we'll see as the game kind of unfolds. We have a plan. We have a target rep count. We'll kind of leave that in-house right now, but excited to see him go do his thing."

Wide receiver DK Metcalf was a full participant all week and will return from the MCL sprain that sidelined him for the past two games. But the Seahawks will be without No. 1 tight end Noah Fant (groin) and backup Brady Russell (foot), in addition to Williams.

Oluwatimi, a 2023 fifth-round pick, was in line to take over the starting job this season until the Seahawks signed Williams to a one-year, $4 million deal on Aug. 11. He has played only four offensive snaps this season and was a healthy scratch four times in favor of undrafted rookie Jalen Sundell, who has been the only other backup center on Seattle's 53-man roster.

Oluwatimi made one fill-in start as a rookie.

"He's a guy that's been knocking on the door for a while," Macdonald said. "Obviously it's an unforeseen circumstance that you've kind of got to take on head-on, but the silver lining in the whole thing is we get to see Olu go do his thing. This guy has been working really hard. Basically started at center for us the whole offseason until we signed Connor. Had a really good week of practice with Connor not here, and onward we go."

Williams made it back for the team's Sept. 8 opener despite being only nine months removed from a torn ACL -- the second of his NFL career -- he sustained with the Miami Dolphins that ended his 2023 season and required surgery. Through 10 weeks, he ranks 25th among centers in pass block win rate and has recently struggled with some errant shotgun snaps, including one he sailed well over Geno Smith's head in Week 8 for a 19-yard loss.

Williams dealt with a speech impediment as a young child, writing in a 2017 article on NFL.com that he was a frequent target of bullies. He was chosen in the second round in 2018 out of Texas by the Dallas Cowboys and played left guard for his first four seasons before moving to center after he signed with Miami in 2022.

"Connor's been in my corner the whole time he's been here," Oluwatimi said. "I've been in his corner the whole time he's been here. Happy for him. He's always going to be my dawg."