Steelers safety Troy Polamalu will miss Sunday’s game against the Chiefs, according to a league source, and a return by the crucial Week 12 meeting with the Ravens is remote at this point.

Troy Polamalu’s latest knee injury doesn’t appear as significant as his last, but Steelers coach Mike Tomlin said Monday the Pro Bowl safety is “questionable at best” for Sunday’s game against the Chiefs.

Steelers safety Troy Polamalu left Sunday’s AFC North showdown with the Bengals because of another knee injury and is doubtful to return.

Teams have released their Week 10 practice participation reports through Wednesday. Here’s a look at some notable developments.

As reported earlier by NFL Network’s Jason La Canfora, former Chiefs RB Larry Johnson cleared waivers Tuesday and is now officially a free agent. And, of course, teams are already being discussed as having interest in his services.

As expected, the Denver Broncos will be without starting RT Ryan Harris against the Pittsburgh Steelers Monday night.

As we reported last week, Steelers safety Ryan Clark will not play in Monday night’s game against the Denver Broncos, according to a league source.

The Steelers listed LB Lawrence Timmons and DE Travis Kirschke as doubtful on the team’s final injury report Saturday, but it’s not looking like either starter will play in Monday night’s game in Denver.

Steelers starting free safety Ryan Clark is highly unlikely to play Monday night in Denver, according to league sources, because of a rare sickle-cell trait that can trigger life-threatening complications at altitude.

San Francisco now finds itself needing to rebound with back-to-back home wins, but the pressure isn’t so much on the players to do so. Whether or not the 49ers can get out of this rut lies squarely on the shoulders of head coach Mike Singletary, writes San Jose Mercury columnist Tim Kawakami.

History shows us that when you disrespect the Terrible Towel, bad luck comes your way. Check out my Put Up Your Dukes segment from NFL Total Access, where I explore the illustrious history of the Terrible Towel.

The Cardinals have no problem bucking convention. Just ask Eli Manning. Does St. Louis have a franchise quarterback in its future? Who believed in Ray Rice? The Steelers police themselves and more from around the Web.

Kansas City Star columnist Jason Whitlock writes that the Larry Johnson distraction is just what Haley and general manager Scott Pioli need, and that the problems Johnson is causing are no reason to cut the guy.

The Vikings won’t have their best defensive back for the showdown in Pittsburgh, but the Steelers will.

Teams have released their practice participation reports for Thursday. Here’s a look at some of the notable players.