At a Tuesday press conference, Steelers coach Mike Tomlin officially ruled out safety Ryan Clark for Sunday night's season opener at the Denver Broncos.

About an hour later, Clark held a press conference of his own. It had little to do with football.

"This week is a terrible week for me every time it comes around," said Clark, referring to his sickle cell trait; the high altitude restricts the oxygen flow to his red blood cells. "I'm trying to turn a terrible week into something positive."

Clark, in conjunction with the University of Pittsburgh Medical Center, the University of Pittsburgh's Vascular Medicine Institute and the Institute for Transfusion Medicine, was formally announcing Ryan Clark's Cure League.

The Cure League aims to raise awareness, donations and support that will enable Pitt research to provide better care and ultimately find a cure for this inherited blood disorder –- one that involves agonizing pain, sometimes requires transfusions and is potentially fatal.

"They pledge money, but more important than that, they pledge support," Clark said of UPMC and others involved with the initiative. "Now my focus is on helping people, trying to put smiles on people's faces who have learned to smile through pain."

Clark, who has the sickle cell trait but doesn't have full-fledged sickle cell anemia, hasn't played in Denver since a game against the Broncos there in 2007. That led to him losing his spleen, his gallbladder, 35 pounds -- and the rest of his 2007 season.

More poignant, he lost a sister-in-law to the same gene that afflicted his red-blood cells.

"Our group is here to find the cure," Clark said. "Money we raise will go to sickle cell research. If we weren't looking for a cure, we wouldn't call it Cure League... but also in my heart ... is finding ways to help people deal with it and its daily struggles."

Follow Steelers reporter Chris Adamski on Twitter @CBSSportsNFLPIT and @BuzzsawPGH.