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

Ciftci has struggled to make an impression on the first-team at Celtic Park since his £1.5million summer move from Dundee United.

Van Hooijdonk, speaking ahead of Celtic’s UEFA Europa League clash with Ajax which is live on BT Sport, was asked if the lack of impact that Ciftci has made at Celtic was becoming a concern.

He 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 Hoojidonk 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 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.”

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.