The Rangers boss is already without David Templeton, Fran Sandaza, Sebastien Faure, Kane Hemmings and Ross Perry.
And he has been rocked by the news that Brazilian defender Emilson Cribari is facing a month on the sidelines, while Andy Little is also a massive doubt for the trip to Ochilview.
Cribari missed last weekend's win over Peterhead and a scan has revealed a tear in a calf muscle.
McCoist is now without his two first-pick centre-backs, with Perry also sidelined due to hernia problems, with the only positive news being the imminent return of Kevin Kyle after a neck injury.
He said: "Emilson has a first-degree tear in his lower calf just above the Achilles, and it looks like he will be out longer term, too. It appears Ross Perry has a hernia problem which will need operated on and that is going to be six or seven weeks sadly.
"We will likely be without these two lads for a number of weeks now. However, I felt Chris Hegarty and Lee McCulloch did well at the heart of the defence last Saturday."
Little has been struggling with a foot problem, and McCoist groaned: "Andy had a scan which has shown severe bruising on his foot which we will have to monitor and be very careful with."