Bristol Rovers centre-half Alfie Kilgour underwent knee surgery on Wednesday, manager Joey Barton has confirmed.
The 23-year-old missed Tuesday's trip to Salford City after limping off injured against Tranmere Rovers on Saturday.
And the defender is set to miss up to three months of action after being operated on to address the problem.
It is not the first time Kilgour has suffered a significant knee injury after tearing his anterior cruciate ligament in 2016.
"He had surgery yesterday," Barton said. "A conservative estimate is six to eight weeks. It could rumble on to 10-12.
"I’ll be down the cathedral this afternoon to get some holy water and sprinkle it on his knee.
"Losing Alf is a blow. He’s been superb as part of that defensive unit and on Tuesday we had to change shape because of his injury, but again we’ve absorbed a few of them and we’re not the only team with injuries."
Kilgour's injury leaves Rovers' short of options at the back and they were forced to move to a back four at Moor Lane on Tuesday, away from Barton's preferred back three.
The manager hopes to have Luca Hoole back in contention soon, but Saturday's trip to League Two leaders Forest Green Rovers may come too soon for the 19-year-old.
Mark Hughes, who has not played for Rovers since the 1-0 defeat at Hartlepool in September owing to an Achilles problem, is also edging closer to a comeback.
"He’s (Hughes) getting there, but I don’t think he’s going to be in contention to start," Barton said.
"Luca Hoole will hopefully train in the next couple of days. He’s expected to be back on the grass today, but Saturday may come too soon.
"Next Saturday gives him a chance, and maybe Trevor Clarke has a squeak for next Saturday. Yozzer, long shot, but hopefully, after that, the three of them are back in contention."
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