Cort has undergone surgery on his troublesome foot injury and is set to miss the remainder of the season with his short-term deal at the club set to expire this summer.
Gunn said: "It looks likely now that we won't have him for the remaining
games after his operation and the recovery period after that.
"His commitment and his bravery we have to commend because he put his body on the line for the club and the more characters we have like that in the squad the better.
"Hopefully for Carl the operation will be a success and it will give him the opportunity to regain his fitness as soon as possible."