Pittsburgh Steelers safety Ryan Clark will not play in Sunday's game against the Denver Broncos due to a sickle cell trait which makes it dangerous for him to play in high altitudes.
Clark was forced to miss the remainder of the 2007 season after suffering a ruptured spleen following a Steelers game in Dec. 2007. He also had to undergo surgery to remove his gall bladder and lost 30 pounds before making a full recovery.
Clark hasn't started any games in Denver since, including the Steelers' wild card playoff game against the Broncos in January, which they lost in overtime.
The 32-year-old LSU product tallied 100 tackles and one interception a year ago. He will be replaced in the starting lineup by Ryan Mundy.