Hillenmeyer, a seventh-year NFL veteran, left in the third quarter with what Bears coach Lovie Smith called a rib injury. That left Roach, a third-year veteran who replaced injured outside linebacker Pisa Tinoisamoa earlier this month, to move inside to the middle spot in Chicago's defense.
Roach also raced into the flat to hound running back Julius Jones and force Wallace to throw too high on Seattle's final play, a failed fourth-and-2 from Chicago's 29-yard line with 30 seconds left in the game.
"It's tough when you go to your third linebacker, but Nate Roach stepped in and did a super job of getting the calls, getting us in the right spot," Smith said.
Roach just shrugged when asked about the void he stepped into with Sunday's game at stake, saying it wasn't much different than replacing Tinoisamoa earlier in the season.
"I mean, I feel comfortable," Roach said. "I think the guys, they trust me. They trust anybody who can show that they are calm under that kind of pressure."
Roach lamented not being able to drag down the elusive Wallace for a safety, then realized the interception and subsequent field goal from Robbie Gould was better.
"Oh, man, I wish I would have gotten him down -- but it turned out being better," Roach said. "We turned out getting three points instead of two."
Forte, who had 66 yards on 21 carries and made a team-high six receptions, limped in the locker room following an extended, postgame treatment session. He had a wrap on his left leg.
Copyright 2009 by The Associated Press