BRENDAN RODGERS paid a warm tribute to Kristoffer Ajer who has excelled since breaking into the Celtic team before Christmas.

The Norwegian, who turns 20 next week, has been superb after being transformed into a centre-half from a midfielder by Rodgers.

Rodgers admitted that it would be hard to drop Ajer, even now Jozo Simunovic is available, for Sunday’s semi-final with Rangers after a run of games which has seen his young charge mature into a fine defender.

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“When I first came to Celtic, Kris was a midfielder and I thought his best position would be centre half,” admitted Rodgers.

“Maybe in Norway, he could play midfield, but I think he has big possibilities at centre half. I knew he wasn’t going to get the games there for me at first, so we loaned him to Kilmarnock to get that positional experience.

“But it was more so that he had to head the ball, because I knew he would be under pressure at Kilmarnock. That’s important if he’s going to do well in the British game.

“He did well there, came back to us and looked as if he’d developed as a man. Then it was just about timing - when to put him in.

“He did well in some of the Champions League qualifiers but still needed more time to develop. Now he’s in the team with a better understanding of the position.

“He has everything. His potential is huge. He’s 6’5, quick, can play football. He’s a very bright boy as well, he knows there is still a lot of learning for him. He’s got this great hunger to get better, which I love in players, and he’s not even 20 yet."

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Rodgers bought experience German defender in January Marvin Compper but injury has meant he’s hardly kicked a ball for the club since then.

The Celtic manager believes the player will get his chance to prove himself at Celtic.

Rodgers said: “Marvin’s qualities are pretty clear for us, his experience and his way of working with the younger guys in training.

“Of course, he wants to play as well but these aren’t fitness games we are playing. I’m certainly not sentimental. We need to pick a team that gets the results.

“But Marvin is a good guy, I like him. Hopefully in his time here he gets a chance to show his qualities."