PITTSBURGH - Pittsburgh Steelers safety Troy Polamalu may play at Cleveland on Sunday despite sustaining at least the sixth concussion of his football career.

Polamalu is listed as questionable, meaning there’s a 50-50 chance he’ll play only a week after being so disoriented during Pittsburgh’s 38-31 victory Sunday he almost tumbled off the Steelers’ bench while sitting by himself.

“He’ll do some testing again tomorrow. He feels better,” Steelers coach Bill Cowher said Tuesday. “This will be to see if he stays asymptomatic. Once again, this is a situation where he’ll have to get clearance from the doctors before any decision is made about his availability.”

Polamalu sustained the concussion after tackling Reggie Bush on Sunday. He had at least three at Southern California — each during practices or scrimmages — and two in high school, partly because of what friends and coaches said was a reckless tackling style in which he launched himself at players headfirst.

Cowher said this was Polamalu’s first concussion in four Steelers seasons.

“I know there has been a history, and the doctors will take that into account,” Cowher said. “I don’t think it’s my place to be judgmental about that. I’ve got to leave that up to the professionals and the doctors and we’ll talk about that and certainly make decisions accordingly.”

Polamalu’s previous concussions were enough of a concern to the Steelers before drafting him in 2003 that he underwent a pre-draft neurological exam. Polamalu was cleared following that exam by Dr. Joseph Maroon, a neurological surgeon who has long worked with the Steelers and other western Pennsylvania football teams on safety issues.

At the time, Steelers director of football operations Kevin Colbert said: “Players are going to get nicked, especially players who play as hard as he does. I think he’ll probably deliver more hits than he’ll take.”

Polamalu, one of the NFL’s top defensive players and an All-Pro safety last season, was woozy after being pulled from Sunday’s game. At one point, he began tilting slightly and almost fell off the bench.

Cowher smiled when talking about Polamalu’s condition, saying it was obvious he wasn’t ready to resume playing a football game.

“I looked at him in the first half and Troy can still talk to you about a lot of things, but it just wasn’t about football at that time,” Cowher said. “If you would have had a good conversation with him, it would have been fine, but he wasn’t ready to talk about the game.”

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Polamalu’s history of concussions could be a worry to the Steelers now that he had one in the NFL. Several Pittsburgh-based doctors, including Maroon, have done extensive studies on football-related concussions that concluded players become increasingly susceptible to additional concussions once they have sustained multiple concussions.

The studies suggest that blows to the head that might not cause a concussion early in a player’s career may do so after that player has sustained more than one concussion, though that threshold number varies by player.

Maroon and Mark Lovell of the University of Pittsburgh Medical Center are among those who designed the tests the Steelers and other NFL teams use to determine when players are ready to play again following a concussion.