"Ryan Clark will not play in Sunday's AFC wild-card game in Denver.

The Steelers safety has the sickle cell trait, and his blood had a violent reaction to the high altitude after a game in Denver in 2007 that almost cost him his life. He had his spleen and gall bladder removed, lost more than 30 pounds and was out of football for 11 months.

Coach Mike Tomlin informed Clark he would not be playing and said it was an "easy decision.""