The defender checked into Murray Park yesterday for the once over from the medical staff but it is hoped he will be back in action for this weekend's trip to Peterhead.
"Hegarty's thigh went into spasm, which is a new one on me, but he seems absolutely fine," said McCoist.
"He has seen the doctor but we don't it expect it to be too serious."
Meanwhile, McCoist was satisfied with his side's display but admitted that the Ibrox club still make life far more difficult for themselves than it needs to be.
At 3-0 up, Rangers were coasting but then allowed Berwick two quick goals to make things nervy.
McCoist added: "There were negatives too. I was really disappointed with the two goals we lost.
"Andy Little didn't defend the front post area well enough at the corner. We spoke about Berwick's corners and set-plays from that side.
"But it's difficult to criticise somebody who leaves with the match ball.
"There were positives and at times some of the football was good and we certainly had a cutting edge to our play today –but we should have had more goals.
The Light Blues boss also insisted he has no concerns regarding the ongoing goal draught of Francisco Sandaza.
The Spaniard has scored just once since moving to Ibrox in August, but McCoist does not see any reason to panic.
"I felt for him in terms of not getting a goal but that was the only thing lacking from his overall performance," he said.
"The argument is that a centre-forward should be scoring goals, but that said, his contribution was very valuable. He makes things happen."