Ravens starting left guard Kelechi Osemele is expected to have back surgery, which will likely end his season and create even more questions for a struggling offensive line.

Ravens head coach John Harbaugh made the announcement on Friday, indicating that the team discovered “some changes” with the back injury that Osemele has dealt with since last season. Converted center A.Q. Shipley will start in Osemele’s place Sunday against the Cleveland Browns.

“He’s not going to play in this game and, going forward, his chances of him playing the rest of the year are probably pretty slim,” Harbaugh said. “There’s a good chance that he’s going to get surgery here real soon. I don’t want to say for sure, 100 percent, because I don’t know if I’m authorized to say that. But I would anticipate that right now. We’ll move forward on that with the guys that we have and we’ll be in good shape.”

Osemele, a second-round pick in the 2012 draft, has started every game of his Ravens’ career. His move from right tackle to left guard before the playoffs last season paid big dividends as the Ravens made their Super Bowl run. The 24-year-old performed so well that some pundits were projecting Osemele and Marshal Yanda as one of the best guard tandems in the league heading into the season.

However, like the Ravens, Osemele hasn’t found last year’s postseason form and he acknowledged last week that his back issues, which forced him out of the Oct. 6 game against the Miami Dolphins after the Ravens’ first drive, were affecting his play. He vowed to get his back “fixed,” though he mentioned doing it after the season.

Harbaugh said that further testing performed on Osemele’s back this week pushed up the timetable. Osemele, who practiced on a limited basis on Wednesday but was sidelined the next two days, wasn’t available for comment.

“The back was just getting a little worse, a little worse as we went,” Harbaugh said. “We went back and looked at it and there are some things that need to be taken care of.”

Harbaugh expressed confidence in Shipley, but also mentioned that third-year guard/tackle Jah Reid “will play going forward” and that rookie tackle Rick Wagner could get an opportunity.

“You want your guys at 100 percent. A.Q. has played well,” Harbaugh said. “He’s played very well when he’s been in there. He’s a football player. He’s always played well whenever he’s played, and he’ll play well. ... We’ll actually be better there, I think, with a healthier player.”

Still, the injury adds to the woes of the offensive line, which has been one of the Ravens’ biggest trouble spots. The group has struggled to open up holes for the running game, which ranks 28th in yards per game (74.0), and 32nd in yards per carry (2.8). Pass protection has also been inconsistent as quarterback Joe Flacco was sacked 20 times in seven games.