The Seattle Seahawks were treated to a Marine Corps helicopter demonstration with a company of five helicopters and numerous military personnel. A squad of Mariners also jumped from the helicopters into Lake Washington and surfaced on the shore of the team's practice fields. (photo by Curtis Crabtree / 950 KJR)

by Curtis Crabtree
KJR reporter
Twitter: @Curtis_Crabtree

RENTON - Prior the the appearance of Marshawn Lynch at team headquarters on Thursday, the Seattle Seahawks worked through their sixth practice of training camp.

It was a rest day for several veterans as the team attempts to manage their workload throughout training camp.

Defensive end Michael Bennett, wide receivers Doug Baldwin and Percy Harvin and tight end Zach Miller each got a day off from work.

However, the injury from Tuesday to defensive tackle Jesse Williams is significantly more troublesome.

Head coach Pete Carroll said that Williams' knee injury is a "serious situation" and could require surgery. He said the team still doesn't know all of the details of the injury, but it's not a good sign.

Williams has dealt with knee injuries for the past three years dating back to his time at the University of Alabama.

Injury Report:

Guard James Carpenter (calf) and linebacker Bobby Wagner (hamstring) missed practice for the second day in a row.

Head coach Pete Carroll said Wagner has a first-degree hamstring strain while Carpenter still has a tight calf. Neither injury is considered serious but the team is playing it safe and resting them for the time being.

Receiver Kevin Norwood sat out of practice again. He's had MRIs and other tests on his sore foot, but it just hasn't improved to allow him to practice yet. Carroll said the injury still hasn't "quieted down" but they are trying various treatments to improve the situation.

Paul Richardson suffered a banged shoulder but is expected back in a day or two.

Defensive end Cassius Marsh suffered a groin pull and was held out of practice.

“(It's) a little bit of a groin thing that we just want to make sure doesn’t go the wrong way," Carroll said.

Defensive tackle Jimmy Staten (knee/hamstring) and tackle Michael Bowie
(shoulder) did not practice. Receiver David Gilreath did not appear to be at practice.

Linebackers Bruce Irvin (hip) and Korey Toomer (hamstring) remain on the physically unable to perform list. Cornerback Eric Pinkins (Lisfranc) remains on the non-football injury list.

Linebacker Malcolm Smith (ankle), safety Kam Chancellor (hip) and tackle Russell Okung (foot) remain sidelined after offseason surgeries.

Roster Moves:

The Seahawks placed tight end Anthony McCoy on injured reserve and signed former USC receiver Ronald Johnson.

Head coach Pete Carroll said that McCoy did tear the Achilles in his left leg during practice on Monday. It's the second straight season McCoy will miss due to an Achilles injury.

Johnson provided some added help at receiver on a day when five receivers did not participate in practice.

The Seahawks will need to make an additional move to bring Marshawn Lynch off the reserve/did not report list on Friday.