Big Ben expected in Steelers' lineup

Pittsburgh Steelers coach Mike Tomlin said Tuesday that starting quarterback Ben Roethlisberger is expected to play this weekend against the Baltimore Ravens.

Roethlisberger took a knee to the head in last week's overtime loss to the Kansas City Chiefs. Tomlin, speaking at his weekly news conference, confirmed that Roethlisberger suffered a concussion but the quarterback passed all of the neurological tests Monday.

"I met with Ben yesterday; he felt normal and he felt fine," Tomlin said. "The battery of tests that he took showed that he showed no symptoms. So we will continue to monitor his condition and where he is on a day-to-day basis and let that guide our decision-making. But as I sit here today, he is symptom-free and feeling fine. So we anticipate Ben practicing tomorrow."

Tomlin left the door open to keep Roethlisberger out of the lineup if there were any setbacks during practice this week. But if Roethlisberger is on the field for practice, he's likely to play on Sunday.

With Charlie Batch out with a wrist injury, the Steelers would have to turn to third-stringer Dennis Dixon if Roethlisberger cannot suit up.

"I've been very pleased with Dennis' progress as a third quarterback," Tomlin said. "That's different, of course, than playing against the Baltimore Ravens on Sunday night television. No question we would have to do some things to help him if he plays in this game."

The Steelers are expected to sign quarterback Tyler Palko to their practice squad this week, a league source told ESPN's Adam Schefter. Palko played at the University of Pittsburgh and was with former Steelers assistant coach and current Arizona Cardinals coach Ken Whisenhunt in Arizona last summer. Recently, Palko had been on the Montreal Alouettes practice squad.

The Steelers, already playing without star safety Troy Polamalu (left knee ligament) and defensive end Aaron Smith (right rotator cuff), also lost left guard Chris Kemoeatu with a sprained right medial collateral ligament in Kansas City. He is expected to be out for a couple of weeks, and will be replaced by nondrafted rookie Ramon Foster.

Tomlin isn't ruling Polamalu out of the Ravens game, calling him "questionable, at best" -- just as he did last week, when it was obvious Polamalu wouldn't play. The five-time Pro Bowl safety could sit out additional games past this one with his second knee injury this season.

Polamalu has missed five games and he played only a few plays in a sixth, a 18-12 loss to Cincinnati on Nov. 15. The Steelers lost four of those games.

This is a big game for the Ravens (5-5) and Steelers (6-4), as both teams are fighting for playoff positioning in the AFC.

James Walker covers the AFC North for ESPN.com. Information from The Associated Press is included in this report.