Two key Steelers players -- linebacker James Harrison and running back Rashard Mendenhall -- were both on the inactive list for Sunday's game against the Broncos. Harrison had minor surgery on his left knee last month, and was hoping to be ready for the opener. However, he missed practice Saturday at which point he was listed as doubtful. Harrison had nine sacks last season. The Steelers' defense is also without safety Ryan Clark, who is out as a precaution because of a blood disorder that becomes particularly problematic at high altitude. Mendenhall's absence is not a surprise. He has been recovering from major knee surgery.