The Gers reached the third round of the Ramsdens Cup with a 1-0 win at Falkirk earlier tonight.
Despite the impressive victory, McCoist claims that his squad was "down to the bare bones".
He said: "I think it was inevitable that we would lose some players. My biggest concern is when we don't replace them.
"I keep going on about the numbers and we've lost in the region of 25 and we've brought in nothing like that, we've brought in a very minimal amount.
"We were down to the bare bones tonight when you looked at the bench. We definitely need to strengthen, of that there is no doubt."
The Scottish Third Division outfit will be unable to recruit new players when a 12-month transfer embargo comes into effect on September 1.