McCombe, who struggled with a back problem for much of last season, got 45 minutes under his belt in the pre-season win at Rossington Main this month and had hoped to be fit for the start of the Sky Bet Championship campaign.
But with little sign of the injury improving, the 30-year-old has been ordered to get the problem fixed properly.
"Jamie is having problems with his back and he'll be out for two or three months," Rovers boss Paul Dickov said.
"It's a long-standing injury he's got and to be fair to Jamie he's tried to play through it the last season or two. But when he came in and we had a look at it we decided it's better for him to get it fixed. He'll be in a cast for a few weeks and we'll be lucky if he's back within two months.
"He's had a stress fracture of his back since his Huddersfield days which he's managed to play through, but if you manage injuries for that long it's difficult to do yourself justice.
"Jamie's done fantastically well to play last season but we feel as a staff that we're better getting him 100 per cent fit.
"If he misses two months, he's still got eight months of the season to look forward to."