Garoppolo undergoes surgery on left knee

Ten days after he sustained a torn ACL in his left knee, 49ers quarterback Jimmy Garoppolo had surgery Wednesday morning.

Head coach Kyle Shanahan did not provide details of where the surgery was performed or whether any further damage was uncovered during the procedure. He also didn’t have a time frame for when Garoppolo might be able to return to football activity in 2019.

“It’s way too early,” Shanahan said. “When he wakes up and I talk to the doctors who did it, we’ll get some clarity.”

Garoppolo will have a rehab partner in running back Jerick

McKinnon, who tore his ACL on Sept. 1. McKinnon was on crutches with a brace on his right knee Wednesday in the locker room.

“Jimmy’s a warrior, and I’m pretty sure he has the same mind-set on the whole process and recovery process,” McKinnon said to reporters. “The only thing we can do is work and push each other through these next nine months — and push each other to be that much better than before.”

Injury report: A troubling sight during practice: Sixty percent of the starting offensive line doing the same rehab work on a side field.

Left tackle Joe Staley, center Weston Richburg and right tackle Mike McGlinchey all sat out practice because of knee injuries sustained in Sunday’s 29-27 loss to the Chargers.

Shanahan has termed them all questionable for Sunday’s game against the Cardinals, but it’s notable that McGlinchey and Richburg returned after they were injured. Staley, who had brace on his right knee, appeared to be walking without a noticeable limp.

In other injury news, wide receiver Marquise Goodwin (hamstring, quadriceps), cornerback Richard Sherman (calf ) and wide receiver Dante

Pettis (knee) did not practice. Running back Matt Breida (shoulder) and guard Mike

Person (knee) were limited. Colbert back: Shanahan indicated free safety Adrian

Colbert would start Sunday after rookie D.J. Reed assumed his spot last week. Shanahan had said Reed started because Colbert had been dealing with a hip injury.

“We’d always lean toward Colbert, because it was his job to start with and he played at an extremely high level last year and started out this year doing that,” said Shanahan. “Been playing banged up for a while. Gave him a chance to get healthier last week. We believe he’s going to be much healthier this week, so I’d be surprised if he wasn’t out there.”