Celtic will take on Old Firm rivals Rangers in the semi-finals of the prestigious cup competition at Hampden Park in Glasgow on Sunday afternoon.
Former Rangers striker Thompson, now on the books of Scottish Championship side St Mirren, believes that the Gers will lose the match and has predicted the tie to be a high-scoring affair.
"I will stick to my guns and say it will be an open game," Thompson told BBC Sport. "I think Celtic will win the match, but I think it will probably be 3-2 or maybe even go for a 4-3."
Celtic will head into the game as favourites and there will be goals, but it is unlikely that there will be seven of them.
Both the Bhoys and the Gers are vulnerable defensively, but it is hard to see more than four goals over the course of the 90 minutes.
Rangers have a good team and some superb players, and Mark Warburton’s side will make it tough for Celtic.
The Scottish Premiership outfit have come into form in recent weeks, and that should be a concern for the Gers.