Ryan Clark, Pittsburgh's veteran starting safety without all the long hair, has the sickle-cell trait. It's a condition that impacts his blood when he exerts himself in the high altitude. Clark lost 30 pounds and nearly died when the Steelers played at Denver in 2007, after which doctors had to remove his spleen and gall bladder, which caused him to miss the final 10 games of the regular season, plus a playoff loss. Clark has missed a total of just four games since, including the postseason.

Doctors had cleared Clark to play when the Steelers returned to Denver in 2009, but coach Mike Tomlin erred on the side of caution at the time and opted to keep him out. Tomlin made a similar call today about Clark's status for the Steelers' wild-card game at the Broncos this weekend. This despite Clark's expressed desire to play anyway, according to what he told ESPN:

"I talked to my doctors and we actually had a plan in place for me to play. All things pointed to me going until (Tomlin) told me I can't. He said he wouldn't have let his son play and so I'm not playing either."

A starter since he joined the Steelers in 2006, Clark led Pittsburgh in tackles this season. Tomlin clearly did not want to have a plan in place in case he died.

Ryan Clark won't play vs. Broncos [ESPN]