Ryan Clark felt the pain in his side during the game Sunday night, but it was not until the bus ride to the airport that he realized something was amiss.

He yawned, and it hurt. Clark, the starting free safety the past two seasons, talked to Steelers internist Dr. Tony Yates and he immediately had him hospitalized. Yates stayed with Clark overnight, and it was discovered that Clark has a blood condition that affects his spleen.

"During the game it was kind of hard to catch my breath a few times," Clark said yesterday after he returned from Denver Tuesday. "I thought maybe I just got out of shape during the bye week, felt maybe I ate too much over the bye week. I couldn't recover after the kickoff team as I usually do to go over and play defense."

Clark said he had the same problem two years ago when he played for the Redskins in a game at Denver.

"They diagnosed it a little differently. They thought it was a little contusion. We're learning more about it now."

Clark said he has the sickle cell trait that runs through part of his family and believes that has something to do with the condition affecting his spleen only at high altitudes.

"There are some other things right now they are researching because they don't feel like just that can cause this type of problem," Clark said. "They'll do more research and results should be back later in week."

Until then, Clark is trying to wean himself off pain pills and hoping he can play Sunday in Cincinnati.

"We'll see, play it by ear. It's one of those things, I could wake up and feel pretty good."

Injury update

One of the better matchups when the Steelers play the Bengals involves Cincinnati right tackle Willie Anderson vs. defensive end Aaron Smith. But Anderson has been ruled out with a recurring knee injury and Smith likely will not play with a sprained MCL in his left knee.

Anderson had a 116-game streak of playing snapped this season. Smith's 115-game streak, including playoffs, will end Sunday in all likelihood although coach Mike Tomlin has not officially ruled him out.

Smith, Clark, linebacker Clint Kriewaldt (shoulder), offensive tackle Marvel Smith (back) and wide receiver Hines Ward (knee) did not practice yesterday.

Ward said he will practice today.

Tight end Heath Miller joined the injury list when he came up with chin and nose injuries after his helmet was smacked during practice.

Cornerback Bryant McFadden, who has not played the past two games because of a high ankle sprain, was limited in practice.

"I'm not sure yet," McFadden said of his possible return. "These next couple days are really going to dictate and allow me to know what I can do."

Cincinnati running back Rudi Johnson did not practice yesterday, although he might return from a hamstring injury that has kept him out of action for two of the past three games.

Not for sale

Cincinnati coach Marvin Lewis said he doubts Bengals fans will sell their tickets to Steelers fans for Sunday's game, as they often have done in previous seasons.

"I think the fans of the Cincinnati Bengals have shown their true spirit and they've come out in droves, and that's a great thing. No longer are we in the days when they sold their tickets to people from Pittsburgh. Hopefully, they'll come out and enjoy a great football game."

Big Ben on Cowher, Tomlin

Quarterback Ben Roethlisberger on how Tomlin differs from former coach Bill Cowher:

"There is a lot of differences, just because they're very different people. The time schedule's different, and I think the way that he talks to you. If you screw up or you make a mistake, he wants to talk to you about it or encourage you, 'You're going to be OK,' whereas Cowher would yell at you or scream at you or something."

Practice squad signing

The Steelers signed defensive end Shaun Nua to their practice squad and released running back Justin Vincent from that unit.

Nua was a seventh-round draft choice in 2005. He spent half of that season on the practice squad and the other half on the active roster, although he never played in a game. He spent last season on their practice squad and was released with their final cuts Sept. 1 this season.