In a conference call on Wednesday, Steelers Head Coach Mike Tomlin updated the statuses of four key players.

Safety Ryan Clark will not play because of a blood disorder that becomes dangerous in high altitude.

Linebacker James Harrison, a Pro Bowler in each of the last five years, practiced for the first time in the preseason on Monday. Harrison has been out of action since undergoing knee surgery on Aug. 15th.

“We’re just taking it day by day and his availability is going to be based on how he feels following some cumulative work over the course of the week,” Tomlin said. “I think Monday’s work was a positive day, but we’ll continue to watch and see where it takes us.”

“I’m coming along,” added Harrison in a separate call.