Old Firm rivals Rangers and Celtic will face each other in the semi-finals of the prestigious cup competition at Hampden Park in Glasgow on Sunday afternoon.
Former Gers winger McCann believes that the tie will be a closely fought affair. The former Southampton and Heart of Midlothian man has also suggested that Celtic striker Leigh Griffiths will be a key player in the encounter.
"I think they are a lot closer in terms of where they were a couple of seasons ago [in Scottish League One],” the former Scotland international told Sky Sports when asked how much closer Rangers are to Celtic. "I said at the weekend, after watching Celtic beat Motherwell, that I believe Rangers have improved an awful lot under Mark Warburton and I'm not sure Celtic have. That is the worry that Celtic fans will have going into this match.
"By the same token, I still think they (Rangers) are vulnerable at the back and that is where Celtic hold the ace in Leigh Griffiths. This game is a lot closer than what it was back then and I think it could go all the way... I really do. I don't think a team will come out and blow the other away.
"If Rangers can replicate the performance they put in against Dundee in the last round, they stand a very good opportunity of winning the match. If Celtic play to their very best, then they probably would maybe just edge it, but Celtic have not been playing at their best and that's what puts the tie in such a perfect balance.”
Celtic have the strongest squad in Scotland, and the Bhoys will head into the tie as favourites.
Ronny Deila’s side have picked up some form in recent weeks, and the Hoops will certainly be determined to do well against Rangers.
Rangers, who won the Scottish Championship title last week and will play in the Scottish Premiership next season, are not as strong as Celtic, but they are an attacking team and will take the game to the Hoops.
Leigh Griffiths has been banging in the goals for Celtic so far this campaign, and he will certainly be keen on adding to his tally by bagging one or two against Rangers.