Cassius Marsh to have MRI on knee

RENTON, Wash. -- Seattle Seahawks rookie defensive end Cassius Marsh will have an MRI on his knee after suffering an injury early in Wednesday's practice.

The Seahawks have high hopes for Marsh, a fourth-round draft choice from UCLA. He had an impressive preseason debut last week at Denver with four tackles, including a sack.

Marsh has looked good in training camp as an aggressive pass-rusher with a relentless style of play. He is expected to be part of the rotation on the defensive line, especially in passing situations.

In other news, Seahawks coach Pete Carroll did an interview Wednesday morning on KJR radio and said offensive tackle Russell Okung would not play in Friday night's game against San Diego.

Okung, who had offseason surgery to repair a torn ligament in a big toe, returned to full participation at practice this week, but the Seahawks will wait one more week before he sees action in a game.

Carroll said two other starters on the offensive line -- left guard James Carpenter and center Max Unger -- will play Friday. Neither played in the preseason opener at Denver.

Quarterback Russell Wilson, meanwhile, said it was good to see receiver Percy Harvin making catches and looking strong Wednesday after leaving Tuesday's practice when he was spiked on his right heel after making a catch.