Nadir Ciftci’s agent Pierre van Hooijdonk has admitted that he is worried about the limited impact his client has made since joining Celtic, and says that manager Ronny Deila is playing him out of position.

Ciftci has struggled to make an impression on the first team at Celtic Park since his £1.5m summer move from Dundee United, due in part to a six-match ban he received for biting Dundee’s Jim McAlister whilst at Tannadice.

With Deila favouring a system that deploys one striker, and with his reluctance to play Ciftci in wide areas, the forward has found his starting chances limited due to the blistering form of Leigh Griffiths.

When asked if the lack of impact that Ciftci has made at Celtic was becoming a concern, van Hooijdonk said: “Yes. I realised from the beginning it was going to be difficult because of the suspension. He only played in the preliminary round of the Champions League and some friendly games.

“The thing is the coach sees him as a number nine and then he has to compete with a real number nine in Leigh Griffiths. I’ve said before I think they are two completely different strikers.

“Leigh is more a poacher and a goalscorer than Nadir is. Nadir has other attributes of the game. He can hold up the ball a bit better, his link up play is better.

“You also need to realise at Dundee United Jackie McNamara let him play from the left side. In that role I haven’t seen him yet. At Celtic he just seems to play number nine or sit on the bench.”

Van Hooijdonk believes that a change to Celtic’s system could be beneficial for all parties, with Ciftci providing a foil for goalscorer Griffiths.

“I said when Nadir signed, looking at the qualities of both players – not just the qualities they have but the qualities they don’t have – they would be the perfect combination,” he said.

“I always find it a pity when you have two good strikers but you play one. In my day – football has changed a bit but it’s still 11 v 11 – I was playing with Simon Donnelly then Andreas Thom. Then when Jorge Cadete came he was my partner up front.

“If you compare the two of us with the two of them now, Jorge was much more the Leigh Griffiths.

I was much more the Nadir. I also liked to be involved in the link-up play. Jorge was always on the last line of defence looking for the final ball to finish it off. He was always in the box.

“When I first signed for Celtic they were shouting at me to get into the box. At that time we didn’t really have somebody else there. But when Cadete came he was always there. So I was still playing the same game I’d played before but we had someone in the box. That’s what I felt was a perfect combination.”

Van Hooijdonk, speaking ahead of Celtic’s UEFA Europa League clash with Ajax, which is live on BT Sport, thinks that the Celtic players need to produce a rousing performance in the match against the Eredivisie leaders to dispel any notion that their manager is under pressure, even if they don’t get the win they need to stay in contention in the Europa League.

He also urged the Celtic support to remain patient, as Ajax’s style of play means that they may enjoy the bulk of possession as they try to draw Celtic out.

He said: “I think that everyone realised after the draw that it was going to be a tough group for Celtic. People would accept it if you don’t get through, but it’s all about the way. What is happening in the games you have played in?

“In the games that Celtic have played, apart from the one in Amsterdam which I felt was a good performance, and maybe the one against Fenerbahce when they unfortunately gave up a two-goal lead, unfortunately in the games that they were expected to take points from they didn’t take any. That leaves them now in a very difficult position.

“From the manager’s point of view, winning the league at this moment in time is not very difficult. No disrespect, but Celtic have got the best squad in the country by far so I don’t think that anyone would bet on any other team winning the league.

“In Europe it’s different, it’s all about how you perform and how your games go. Even if your results are not going your way, you can still make an impression. That’s exactly the reason why these upcoming two games are very important against Ajax and Fenerbahce.

“The only worry that I’ve got for Celtic is because of the home support they will push the team and Ajax are very good at keeping the ball, they have a great possession game and that can frustrate the fans.

“If a team at Celtic Park is having the ball in their own half or at the back for quite a bit then the fans lose their patience, they start to scream, they shout get forward and the danger is you start running like a headless chicken because of the push you feel from the crowd.

“And Ajax are capable of playing through the lines and they can finish you off. That is a danger.

“On the other side I feel the physical presence of Celtic should be important. Feyenoord played Ajax last month and while Ajax have the better player and played Feyenoord off the park in the first half, in the second half Feyenoord started to win more of the battles and the game completely changed.

“They don’t like the physical part of the game. Feyenoord beat them in that game and Celtic should try to hurt them where they can and that is by making the game physical.”

Watch Celtic v Ajax in the UEFA Europa League live and exclusive on BT Sport 2 from 7.30pm on Thursday. Visit btsport.com/Europe for more info.