Outside linebacker James Harrison admitted Friday that there are no guarantees in life -- although the Grim Reaper and IRS would beg to differ -- but it's highly probable that Harrison and strong safety Troy Polamalu will miss the game Sunday against the New York Jets.

Neither practiced at all this week and each was listed as questionable in the end-of-week injury report. Coach Mike Tomlin prefers that an injured player practice at minimum on the Friday before that week's game. Harrison, who underwent arthroscopic surgery Aug. 15 on his left knee, agreed that it's a good idea to first work at least one day of practice. This from a perennial Pro Bowl choice who hasn’t practiced since Sept. 3 and missed the entire preseason.

"I feel great,'' Harrison said, as he unwrapped a large icebag off his recovering knee. "It's up to me if I play, because they don't know how I feel. I know how I feel. If I feel like I can go, I'll go. If I don't, then I won't.”

Speaking of those guarantees in life, Harrison responded grimly when asked about injuries becoming chronic at age 34: “I hope it gets better this season, (but) nothing's certain. I could walk out of here today and die.

"What it comes down to is that there's no need to hurry up and rush yourself back, end up doing more damage so you have to deal with the injury for the rest of the season. ... (Maybe it’s better to) sit out a few weeks and get it back healthy rather than to go play a game (and) re-injure it.”

Polamalu, who strained his right calf late in the Denver loss, deferred to Tomlin any talk about him being available for Sunday. Yet he agreed with Harrison that it’s better to sit now and heal completely.

"Yeah, you definitely don't want injuries nagging you the entire year, but you never know what these AFC matchups mean for the future, either,'' Polamalu said. "But you definitely don't want to get an even worse injury and endanger your entire season. The more you practice, the better you are for the games. So, we'll see what happens.''

Polamalu missed two games in 2010 and none last season, while Harrison sat out five games last season -- one by suspension and four after fracturing an orbital bone.

Starting roles: In the absences of Harrison and Polamalu, Chris Carter is expected to start for a second consecutive week, with Jason Worilds in reserve at both OLB spots. Ryan Mundy moves from starting at FS for Ryan Clark (sickle cell trait) last week to SS for Polamalu this week. “I’m definitely prepared,” Carter said. “Looking at the films, you saw some misfits here and there. The Denver game was of benefit for us as a defense and me personally.”

Injury report: In addition to Harrison and Polamalu being questionable, the Steelers listed backup ILB Stevenson Sylvester (knee) as out and RB Rashard Mendenhall (knee) as doubtful. Deemed probable were starters OT Max Starks (illness), DE Ziggy Hood (back) and backup RB Jonathan Dwyer (heel).

Follow Steelers reporter Chuck Finder on Twitter @CBSSteelers and @cfinder.