Deila upbeat despite midfield absentees for Celtic's crunch Europa League tie

Ronny Deila insists a decimated midfield has not left him fearful ahead of Celtic's crunch Europa League clash with Ajax at Parkhead.

At the pre-match press conference at Celtic Park, the Hoops boss revealed that skipper Scott Brown could be out for up to three months with a knee injury picked up against Kilmarnock at the weekend.

The Scotland captain, who had a scan on Monday, was back against Killie after missing four matches with a knee injury, but Deila confirmed he has suffered a different complaint ahead of Thursday's match.

Kris Commons is still likely to be out with a combination of illness and a hamstring injury, while fellow midfielders Nir Bitton and Stefan Johansen are suspended for a match when defeat will end any hope of progressing from Group A.

One piece of good news for the Scottish champions is that Charlie Mulgrew, who can play midfield or defence, is back in contention after recovering from a thigh injury, but he has not played since September.

"Scott Brown is out for a while,'' Deila said. "We don't know for sure yet but I heard it's eight to 12 weeks.

"It is nothing to do with the previous one. It was very unfortunate in a challenge near the end of the game.

"We hope that (an operation) is not necessary. We are waiting for the experts to look at the pictures so we can be even more sure what to do, if it is going to be an operation or not.

"It is always tough to lose your captain but, having said that, in the last period he was out we won a lot of games.

"Kris has been a little bit sick but he had the injury after the Molde game. It is likely it will be a little too early. He trained today but was not feeling at his best.

"I am not fearing anything but of course there is going to be big changes in the midfield.

"We have to put together a new one but we have a lot of good players and we are going to have a good team.

"Of course it is more tricky, a lot of the experience is out but again we have players who can fill those roles.''

After back-to-back defeats at the hands of surprise package Molde, Celtic sit bottom of Group A with two points from four matches, while opponents Ajax are one point ahead.

Norwegian outfit Molde have qualified with 10 points and play Turkish giants Fenerbahce, who are second with five points.

While a draw could still see Celtic get through, wins against the Dutch side and Fenerbahce in their final two games will definitely take them into the knockout stages and Deila is banking on needing those six points.

"We have a very clear match plan of what we want to do tomorrow, players know what is expected,'' the former Stromsgodset boss said.

"It is just to go out and enjoy the match, that is important. There is nothing to fear - it is a football match where we have a big opportunity.

"I want to see energy, players that want to show their best and want the ball and fight as a team and then I know that we have qualities that can win the game for us.

"We have to go win the game and I think that is the same for Ajax.

"They want to win so it is going to be a very interesting game and I am really looking forward to it.

"It is a big game and a big opportunity to get three points, it puts us in a situation where we can do it ourselves in the last game in Turkey.''