Citing league sources, NFL Network's Jason La Canfora reported earlier this week that Clark is highly unlikely to play.
Clark nearly died following a game in Denver two years ago because of a rare blood disorder that is aggravated by playing in high altitude. While Steelers coach Mike Tomlin hasn't publicly said so, he is believed to have told Clark to sit out the game.
Clark has been given medical clearance to play.
"Itâs still a tough decision,â Clark said Thursday. "Competitively in this game, everybody has a little bit of ego. I want to go back and play there. Not for the sake of really beating the Broncos, but in the end, God gets the glory that I am able to come full circle and I am able to go there and play.
"The doctors cleared me. It's still a decision between my family and I. I think the part that makes it bad by not having a decision made is the practice time. That is the unfair thing. Itâs a tough decision."
Clark had his spleen and gall bladder removed during separate operations, and he lost 30 pounds after the Oct. 21, 2007, game in Denver, which ended his season. Many of Clark's teammates told him he should skip the game.
The Associated Press contributed to this report.