SEATTLE -- The Seattle Seahawks will be without sixth-overall draft choice Russell Okung for at least two weeks after he left Seattle's second preseason game with an ankle injury, a source told ESPN.com's John Clayton.
Results of an MRI on Sunday showed the left tackle to whom Seattle just guaranteed $29 million has a mid-ankle sprain, according to the source.
The team was concerned after Green Bay beat Seattle 27-24 on Saturday night that Okung had suffered a high right ankle sprain. Those sometimes take two months or more to heal.
"It's pretty significant," coach Pete Carroll said Saturday night of the loss of the foundation to his changing offensive line. "Obviously we made it as big a priority as we could make it to get him."
Carroll said he didn't know how Okung got injured, only that it stings the entire team that is banking on improved offensive line play to lead a comeback season from 9-23 the last two years.
He sprained the same ankle in Oklahoma State's opener against Georgia last season but missed only a few plays. The 6-foot-5, 310-pound stalwart started all 13 games for those college Cowboys last season, though the ankle continued to bother him late into the year.
Mansfield Wrotto, normally a guard, replaced him. Seattle is already without backup tackle Ray Willis for an indefinite time because he is facing knee surgery.
After Okung missed the first eight days of training camp because of a contract impasse, the Seahawks gave him a six-year deal earlier this month that has a maximum value of $58 million.
Information from The Associated Press contributed to this story.