GABRIEL Reuben could be part of a very exclusive club in Brazil next summer but he seems destined to endure a winter of discontent in Ayrshire.

The Nigerian midfielder is likely to be one of just four players from the SPFL Premiership to go to the World Cup finals - and the only one from outside Celtic Park - but is still not rated highly enough to be given a game by Kilmarnock.

Reuben has spent the last week as part of the Nigeria squad which secured a place at the finals next year by defeating Ethiopia in a play-off, before facing Italy in a friendly in London on Tuesday night. On both occasions, Reuben did not get off the bench - he was an unused substitute - but that is a lot closer than he has been to getting a first-team game under Allan Johnston.

The Kilmarnock manager will not select Reuben against Motherwell at Rugby Park tomorrow and the 23-year-old - who has not kicked a ball all season for the Ayrshire club - will be training with the youth team after taking to Twitter to criticise his manager and Michael Johnston, the club's chairman.

"I speak the truth, I am not happy," wrote Reuben, who signed a three-year contract in April when he joined from Kano Pillars. "Manager say he don't see me train when I train everyday. Unfair treatment by two Johnstones [sic]. Very strange. I train with you everyday for months working hard. I'm ready to play for the fans. This is why I come to Scotland."

Reuben was posted that message while in London on international duty. Yet Allan Johnston was unmoved. "I have not seen them [the tweets] but one of the boys mentioned it," said the Kilmarnock manager. "You wouldn't be happy not playing, so you can understand that but I don't see the point saying anything on Twitter.

"You have to deserve to be playing and just now we have better young players coming through. Maybe that is because he is coming back from long-term injuries. He has only played two games since, so maybe we haven't seen the real Gabriel Reuben yet.

"He hasn't spoken to me. He is a quiet lad and he hasn't said much, apart from on Twitter which is an easy place to say it. He will need to do a lot better. He is not in the plans and we have really good players coming through, like Craig Slater and Jude Winchester, so the last thing you want to do is stop their development. It doesn't matter what you have done before. You need to deserve to play in the first team. He needs to do better. In the games he has played, he has not done well.

"I am sure he will be the same [after being away with Nigeria]. He just doesn't look up to match speed. Maybe it's lack of games, lack of match fitness. He is obviously a good player because he has been called up to play for Nigeria but he has not done enough to be playing in our first team. It is a football decision."

That might have been end the of it, had there not been further suggestions that not all of the terms of Reuben's contract are being met by his club. Kilmarnock have since started an investigation following rumours that the midfielder had not been paid his full wages or a living allowance that he is due as part of his deal.

Those suggestions are understood to have been made on the player's Twitter account, with the Rugby Park club looking into the incident to discern whether the comments were made by Reuben directly, on his behalf, or by a third party. Michael Johnston was quick to denude them of any sense of truth, though. "I can state categorically the club has paid Reuben Gabriel the appropriate salary he is due since signing his contract with the club," said the Kilmarnock chairman.

Tony Harris, who represents the midfielder, was not appeased, though, and last night claimed there were issues which he has taken up with the Rugby Park club. He also remained adamant that his client is fit enough to play a part in the Kilmarnock first team, while remaining insistent that Reuben was within his rights to voice concerns about his time in Scotland on social media.

"I support Gabriel 100%," Harris told STV. "He's done nothing wrong but expressed his frustration. There's only so much a person can take. Indeed there are some outstanding issues but at this stage we are addressing them directly with the club and therefore it isn't appropriate to comment on it now.

"We expect that these issues could be resolved shortly. In the meantime Gabriel is very fit and ready to play. Kilmarnock should stop messing about with Reuben and fulfil all their contractual obligations to him before things really get out of hand."

The situation served to cloud the club's preparations for a match with Motherwell tomorrow, although Allan Johnston was still able to find a shaft of light. The return of Kris Boyd to the Scotland squad ahead of a friendly against Norway earlier this week was a source of pride for the Kilmarnock manager and he is quite confident his striker can become a regular for the national side again.

"I was absolutely delighted for him," said Johnston of a player who had not been called up to a Scotland squad for three years. "It's a massive lift for him personally and also for the club to have someone represented with Scotland.

"People forget his age because of what he's done. He's only 30, he's still got a long way to go in his career. So it was no surprise to me that he was called back up. Now it's up to him to push on and get himself into the starting XI [for Scotland]. Scoring goals is the hardest thing to do in football and he does it naturally, that's what he's all about. I've got no doubts he can get there again."