The comes a week after Okung sustained a toe injury during Seattle's victory over San Francisco. The team had already planned to keep their prized offensive tackle sidelined during this weekend's game against the Jacksonville Jaguars.
The team will give Okung a designation that would allow him to return, if healthy, after missing the next eight games. If his rehabilitation goes as planned, he'll be eligible to begin practicing with the team in six weeks.
Some Seahawks fans feared that Okung's injury would be season-ending, a possibility that coach Pete Carroll wouldn't rule out last week.
Paul McQuistan will slide over from left guard to left tackle in Okung's absence, starting in his new position against the Jaguars on Sunday.
Okung was Seattle's first round draft pick in 2010 and he has paid off for the team, starting in 15 games last season and winning a spot in the 2012 Pro Bowl.
Seattle remains a 19.5 point favorite against the visiting Jaguars.