AFP - Ben Roethlisberger and Kurt Warner, the quarterbacks from last season's Super Bowl, were forced out of their NFL games Sunday after receiving blows to the head.

Pittsburgh's Roethlisberger left the field in overtime of the Steelers' 27-24 loss at Kansas City, while Arizona's Warner departed in the second quarter of the Cardinals' 21-13 victory over St. Louis.

Roethlisberger had thrown for 398 yards and three touchdowns when he apparently took a knee to the helmet when he was sacked.

Steelers coach Mike Tomlin said he was not certain how severe the injury might be.

"He took a blow, needless to say, it was a concussion-oriented thing so I doubt he was going to come back into the football game," Tomlin said. "I don't have a lot of information in terms of where he is or his level of availability. We will have more information as we proceed."

Warner appeared to be hurt when his head was driven into the turf on a blitz.

Warner lay on the field for several seconds, got up and stayed in the game for the last six plays of a 90-yard drive. He was replaced late in the second quarter as a precaution for what the team called concussion-related symptoms

"I felt pretty good coming out right after halftime, but I just wanted to be smart," Warner said. "It was one of those situations where I didn't feel perfect."

St. Louis quarterback Marc Bulger said he took a blow to the head on the team's final possession, apparently on a sack, and was to be evaluated on Monday. He, too, said he felt fine after the game.

The high-profile injuries came on the same day when Fox television reported the NFL is developing a policy to have teams work with independent neurologists on concussion issues.

In a league where playing through injury is common, and often expected, the issue of long-term damage from head injuries has become a hot topic.

NFL commissioner Roger Goodell and players' union director DeMaurice Smith recently testified before Congress at hearings on football head injuries.

Goodell has suggested players should tell their teams' medical staffs if they suspect teammates have concussion symptoms, but Smith says players shouldn't be asked to police each other.