Ronny Deila has issued a hands off warning after Stefan Johansen was linked with a move to Premiership strugglers Aston Villa – and he has told the player that if he is going to quit Celtic then to make sure it is for a bigger club.

Deila believes that a move to Villa Park would be a step down from Celtic.

Johansen has been an integral part of Deila’s midfield, despite never quite being able to recapture the form that made him the PFA Players’ Player of the Year last term.

A new deal has been on the table for Johansen from Celtic for some time now, but the player has yet to commit his long-term future to the club – but Deila dismissed interest from elsewhere and remains adamant that he does not want to lose Johansen.

“We want to keep Stefan,” said Deila. “He has been very, very good for us. We want to keep him, that’s for sure. He is an important player for us.

“He has had a fantastic career at Celtic. Yes, he has had a dip but who has not had that in their career at Celtic? But in the last 3 or 4 games he is back to playing well, intercepting balls and winning balls and tackling hard. He is a good football player.

“I haven’t heard anything about this thing and there are always rumours about these things. We want to keep Stefan, that is how it is.

“If they [Villa] get relegated then they are in the Championship. Aston Villa is a big club, but for me you have to see the level they are playing at.

“If you are playing in the Premier League, it is a step up, no doubt about that, but they are not a bigger club than Celtic, that is for sure.

“A lot of our players do not want to leave Celtic and a lot of other players who have left Celtic have then thought ‘why did I do that?’ I understand what is happening – it is because of the level and the money. But if you do that then go to a team that plays in the Premier League and can stay there.”

Meanwhile, Ljuban Crepulja is easing his way into training at Lennoxtown with a view to a permanent deal. The 22-year-old midfielder comes recommended to Deila and it remains to be seen if an offer is made to bring the player into the club before the window closes.

“We will see us and we will look at him,” said Deila. “So far he has looked a technically good player but the exercises we had – because of the game on Tuesday, hasn’t been at the tempo we normally have so it’s been a little bit hard to judge. That’s why we want to see him for a little bit longer.

“He is a technical, creative player, a midfielder who can play centrally. He is still young and he has talent. He has quick feet and a good understanding.”

Michael O’Halloran, however, is a player whom Celtic do not appear interested in taking to the club. The player has been a target for Rangers in the window and although his father is involved at the youth structure for Celtic, the Parkhead side are not pursuing any interest in him.

“We are well aware of what is going on around us and we have to do the things we feel is right,” said Deila. “Right now we don’t feel it’s quite right to go in that direction.”

Contract talks are ongoing with James Forrest, Tom Rogic and Stefan Johansen while Charlie Mulgrew is also liable to be offered a new deal once he has returned to fitness.