CHARLIE MULGREW is facing a fight to be fit for Celtic’s vital Champions League qualifier against Qarabag tomorrow night.

The Scotland international, so important for his club on the European stage, is suffering from a ligament injury in a knee which he picked up in the 2-0 victory over Rennes on Saturday.

Assistant manager John Collins admitted the 29-year-old is struggling to be ready for the third qualifying round, first-leg tie against the Azerbaijanis, and that Celtic would not be the same without one of their key men.

Collins said: “Charlie never trained yesterday so we will see how he is. He has been playing very well, so he would be a big loss if he doesn’t make it. He’s such a versatile player for us.”

Kris Commons is also expected to miss out again, a broken toe having not healed properly.

Collins also admitted that, should Celtic go out of the Champions League at this stage, there is every chance that Virgil van Dijk could leave during this transfer window.

Everton manager Roberto Martinez did not try to hide his own admiration for the Dutch centre-back at the weekend and is almost certain to make a bid at some stage.

Collins, however, genuinely believes the 24-year-old will stay for one more season if Celtic make it through into the group stages.

He said: “I am not surprised there is talk. When you are a good player there is going to be speculation. It’s another club mentioned today, I am sure there will be another next week. He’s a Celtic player.

“Will it be more difficult to keep him (if Celtic go out)? Probably. Hopefully we won’t have to deal with that scenario.

“He trains very well and is fully focused. He’s 24 now and has matured. He understands. There has been plenty of talks with Virgil. He has to focus on what he can control – his training and his performances.

“For me, the biggest competition in the world is the Champions League. That’s where every player wants to play, every coach wants to coach and every supporter wants to be. It’s the biggest and best.

“You are up against the best players and coaches in the world. It’s exciting for everyone involved.

“If you are a centre-half playing in the Champions League, you are up against the best forwards in the world. It’s a great challenge and if you do well in that tournament, it puts you on a different level.

“People look at you in a different light if you are taking care of top-class strikers. There is also the financial part of the story, of course.”

Collins hinted that Celtic had not given up on signing another player, even if nobody else moves on.

He said: “We have a good, healthy squad. But, like every manager or coach will tell you, it can always get better.

“You always look at players to improve each department. It’s not easy. Obviously there are financial constraints, but there are also good players at the club, so it’s not always easy to get better ones in.

"Time will tell if we bring any more in."