Davie Martindale fears it will be pre-season before he sees Gavin Reilly back in action after revealing the Livingston striker has suffered a 20-centimetre hamstring tear.
The Lions boss admits the injury suffered by the former Hearts and St Mirren ace in last week's defeat by Rangers was one of the worst he has ever seen.
And he believes it may have been caused by the ultra-fit 27-year-old being too lean.
Martindale said: "Gavin's got a 20cm tear in his hamstring. He's absolutely devastated.
"It's not a good one and not what I wanted to hear.
"To be honest I don't think I've heard anything as bad as that.
"It's not torn off the bone, so the ligament is OK and the tendon is slightly off the bone but is not too bad. Normally it can come off the bone through the tendon. The tear isn't great but it's not the worst.
"It's season-ending. It's potentially a, 'I hope to see you in pre-season' job. It's a four-monther give or take depending on how he heals.
"He's one of these guys with low body fat and a lot of muscle mass. There's real definition to him, almost like a sprinter's body.
"So his make-up is quite tight because there's not a lot of fat to him. But some boys are almost too conditioned and have too little fat in them. You need to have a bit of fat in the muscle to give it that elasticity."
Martindale will have to put his faith in strikers Scott Robinson, Jay Emmanuel-Thomas and Matej Poplatnik as Livi go in search of the single point from their two remaining pre-split games needed to clinch a top-six place, with Hamilton first up at the Tony Macaroni Arena on Saturday.
A top-half finish for the second year running would be a massive financial boost for the Lions but Martindale admits he will not see a penny of the prizemoney, with the windfall required to repair the damage done to the club's balance sheet by Covid.
"My job is to try to finish as high as possible in the league," he said. "Would top six mean an increase in my budget? Probably not.
"My budget is based on finishing 12th. So if we go down next year, it means the club is not losing thousands of pounds and every single player who signs has a relegation clause in their contract because we can't afford to pay those wages if we drop down.
"Our budget would probably go from £1.2million to roughly £400,000.
"When we got promoted from the Championship our budget was £375,000. When we won League One it was £275,000.
"I don't get the cup money, I don't get season-ticket money because all that is needed to pay the other bills we have throughout the year.
"We sold Lyndon Dykes in the summer but all that did was cover costs.
"We've lost 55 per cent of our revenue – which is normally £3million a year – and we've basically pulled that in from selling Lyndon."
