Now he is backing Camilo Duran to do the same against Benfica.

Martin O'Neill's side face a tough task against the Portuguese giants, who have a star-studded squad assembled for hundreds of millions, and thumped Hearts 6-1 earlier this season.

But O'Neill has a history of results against huge clubs in his first spell in charge at the club. And Watt feels that if his old club can put on a solid defensive showing, they have Duran who can make the difference at the top end of the pitch.

He told the Scottish Sun: “Duran is probably one of the best players in the league right now and one of the five best signings of the summer.

“He has a clinical edge and I actually prefer him on the wing rather than through the middle, although I know many people who disagree.

“You want him on the ball as much as possible and he can still produce a striker’s numbers from a position on the side.

“He’s a player who can instantly improve the team. You saw that with the goal he scored at Motherwell on Sunday.

“It’s great that the likes of Duran and Mika Baur are being recognised on the international stage and winning their first caps.

“These aren’t just small nations either. You’re talking Colombia and Germany, two of the top 13 countries in the Fifa rankings, so it says everything about their performances for Celtic.

“Listen, I know Celtic have been a little bit exposed in Europe on the counter- attack and the transition this season.

“But if they can tighten up a bit defensively on Thursday night, I’m sure they can get a result. Duran could be crucial.”