Pocic, 25, started 14 games last season, finding a home at center after playing both guard positions over his first three seasons. He ranked 16th last season in ESPN's Pass Block Win Rate as a center. The 2017 second-round pick out of LSU has made 30 starts in four seasons.
The Seahawks' offensive-line moves have carried added intrigue with quarterback Russell Wilson publicly airing his frustrations with the organization last month. Fueling some of those frustrations was all the hits he has taken behind an offensive line that he wanted to see upgraded.
The Seahawks needed a replacement at one guard spot with Mike Iupati retiring and Jordan Simmons, who shared time with Iupati last season, not being tendered as a restricted free agent. Seattle could re-sign Simmons for less than an RFA tender would have cost.
In addition to Pocic, Seattle has three other O-line starters from last season under contract for at least one more year. Left tackle Duane Brown and right tackle Brandon Shell are signed through 2021 while right guard Damien Lewis, last year's third-round pick, has three years left on his rookie deal.
The Seahawks signed B.J. Finney in free agency last March to be their starting center, but he showed up to camp out of shape and was beaten out by Pocic.
Pocic becomes the third player the Seahawks have re-signed since the negotiating window opened Monday. The others are defensive tackle Poona Ford and special-teamer Nick Bellore. Seattle has made two free-agent additions: cornerback Ahkello Witherspoon and tight end Gerald Everett.
The Seahawks began the week with roughly $17 million in cap space, so they might have to make moves to free up more room.
Pocic's return to Seattle on a one-year deal was first reported by the NFL Network.