Atlanta's McClure, Seattle's Williams injured
McClure had a knee injury the team said, while Williams sustained a concussion. McClure was replaced by Joe Hawley.
Williams' injury briefly appeared more serious as he was face down on the field after delivering a block on Marshawn Lynch's 11-yard touchdown run. Williams got up and jogged off the field on his own.
Coach Pete Carroll said afterward that Williams had a concussion, but didn't have any details on its severity.
Seattle's most serious injury was sustained by linebacker Matt McCoy. During punt coverage in the first quarter, the outside of McCoy's right leg was crashed into by teammate Aaron Curry, with McCoy's right knee bending inward badly. He was helped off the field on a cart.
Carroll did not go into specifics about McCoy's injury. McCoy has also rotated in on defense during passing situations.
''That's going to hurt. He's done a beautiful job of playing those snaps and giving those other guys a break and they also have to double him on special teams,'' Carroll said. ''We're going to have to take a look and see how serious the injury is.''