The Chargers (4-8) have reached the desperation point with their O-line for this Sunday’s game against the Steelers (7-5) in Pittsburgh. RT Jeromey Clary (knee) is listed as out. LG Tyronne Green (hamstring) is doubtful and LT Mike Harris (ankle) is questionable.

Coach Norv Turner is hopeful Harris will play if he shows dramatic improvement, but he's not holding his breath. “In our experience, questionable doesn’t play a lot,” Turner said.

The Chargers current projected starting O-line: RT Reggie Wells, RG Louis Vasquez, C Nick Hardwick, LG Rex Hadnot and LT Kevin Haslam.

Wells, an 11-year vet who has played previously with the Cardinals, Eagles, Panthers and Bills, was signed on Wednesday. Hadnot started the season as a utility backup and was promoted from the practice squad on Nov. 24th. The first time he saw Rivers in a huddle is when he subbed last Sunday.

Wells hasn't played this season and admitted he will likely be winded by the end of the game. “We have worked him pretty good,” Turner said. “Obviously, you have to be aware that he hasn’t been doing a lot. There is a fine line between over working him and not having him ready for the game physically.”

Turner indicated that, in his experience, injuries are more likely to occur with players who are out of football shape. “We have real concerns about that,” Turner said. “We have tried to look at all the different things that could happen, and we got a plan.”

The probable backups on the O-line will be G-T Stephen Schilling and C Colin Baxter, who have also not played in a game this season. They were signed on Tuesday, and it's likely that neither received any snaps with the first team in practice this week.

“It’s an unusual circumstance,” Turner said. “These guys are competitive, and I think they look forward to the opportunity to play. They are going to get on a plane Friday and Sunday they are going to play against the Pittsburgh Steelers. I don’t know that you can ask for a better situation than that.”

QB Philip Rivers has never missed a game since he became the starting QB in 2006. Turner plans to play Rivers this week because they both believe the game is winnable. “We are going to do everything we can to go win a game,” Turner said.

Stuckey back: S Darrell Stuckey, the captain and star of the special teams, will likely play Sunday after missing last week’s game. Stuckey (hamstring) fully participated in practice on Thursday and Friday and is listed as probable.

Brown done for the season: WR Vincent Brown became the first NFL player to be placed on the new reserved-injured designated for return list after he broke an ankle in the second preseason game, but he will not return this season. “He’s not ready,” Turner said. “He’s working and he’s making progress. He ran some routes this week, and I think he’s getting closer, but he certainly isn’t ready to go and play in an NFL game.”

Injury report: Out vs. Steelers: ILB Donald Butler (groin), RT Jeromey Clary (knee) and WR Eddie Royal (hamstring). Doubtful: LG Tyronne Green (hamstring). Questionable: Harris (ankle). Probable: OLB Jarret Johnson (back), SS Corey Lynch (quad), TE Dante Rosario (hamstring) and S Darrell Stuckey (hamstring).

Game preview from a Chargers perspective: Chargers Game Preview vs. Steelers: Analysis, prediction, TV info.

Game preview from a Steelers perspective: Steelers Game Preview vs. Chargers: Analysis, prediction, TV info.

Follow the Chargers and Dan McLellan on Twitter @CBSChargers and @sandiegosports.