Kansas City, Mo. ? Left tackle Kyle Turley was unable to practice again Friday and probably will be unavailable Sunday for Kansas City’s game against San Francisco.

Turley, a former Pro Bowler, is attempting a comeback after a two-year absence following back surgery. He sat out practice all week because of what was described as a sore back.

If he can’t play, he will be replaced by Jordan Black, who struggled last year while subbing at left tackle for the now-retired Willie Roaf.

Coach Herm Edwards said Turley would be a “game-day decision” but that he probably would not play.

“He’s still questionable. I had a good talk with him again today,” Edwards said. “He just has some stiffness. He wants to participate, wants to play. But right now, it’s tough for him to do what he needs to do. I’m not going to say (Turley) is out. Not yet. He could still get better and we could use him as a limited backup guy.”

Turley was signed in the offseason to compete at right tackle, which was vacated when John Welbourn retired. But he was switched to starting left tackle when Roaf, an 11-time Pro Bowler, retired just before training camp began.

Black has spent his career shuffling between right and left tackle.

“There’s really not much different right now than last year,” Black said Friday. “Last year, I’d get a week. I’d find out the beginning of the week what position I’d play, and I’d play it. It’s kind of the same situation right now. I found out this week I was going to play left tackle, and I had a week to prepare.”

Turley and quarterback Trent Green are the only players on the Chiefs’ injury list. Green is out indefinitely recovering from a concussion.

Edwards said there was no reason to think Turley would be out long-term. He also said he doesn’t know if the problem was related to the back surgery.

“I don’t get into all that doctor stuff. I just know he’s sore. He’s not as well as he needs right now to practice. We’ll take it all the way up to game time and figure out where he’s at.”