Celtic star Sead Haksabanovic is at the centre of a messy transfer row that has ended up at the Court of Arbitration for Sport, which will rule on a dispute involving the Montenegro star.

The Hoops ace was named as the Premiership Player of the Month for November and has been a key signing for Ange Postecoglou since he signed from Rubin Kazan in August.

But a dispute involving one of his previous transfers has gone all the way to the highest sports court in the world, based in Switzerland.

Haksabanovic moved from Swedish side IFK Norrkoping to the Russian club last year for £4.75 million, of which former club West Ham were entitled to around £1 million because of a sell-on clause when they sold him back to Sweden in 2020.

However, Norrkoping complained to FIFA because they failed to receive full payment for the 23-year-old, with Rubin claiming they were unable to pay because of sanctions against Russian football and their club.

And with FIFA unable to resolve the dispute, Haksabanovic's case will now be heard by the Court of Arbitration for Sport in the new year and he may have to appear to give evidence.

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Norrkoping chairman Sakarias Mardh said: "We still have outstanding claims for the deal and we are now trying to get the full payment money in.

"We continue to seek help from our lawyers to see if it can be resolved.

"It is up to FIFA and CAS to decide.

"I have great hope that we will get it right in those instances. It is a step in the right direction."

Haksabanovic insists there is more to come from him after being named as the SPFL Premiership Player of the Month for November.

The Montenegro said: "It feels really good," he said. "I think I’ve done alright, hopefully I can get more goals and assists so I can help the team win, and I’m enjoying myself. I know what I can do but I didn’t expect I would win player of the month. I am just happy to be here.

"I would say there is more to come from me. I came without playing any games before I came. Now I have some games in me, so hopefully I can improve every day out here training, working hard, hopefully I can do more and score more goals.

"He [Ange Postecoglou] has given me confidence, he is telling me you can do your one on ones and don’t be afraid."