Manchester City's attempts to placate Robinho and keep the most expensive footballer in England happy have failed, with the Brazilian desperate to leave in the January transfer window. City are aware of his position and, despite strong denials on their mid-season training camp here in the United Arab Emirates, they have reluctantly accepted that the player whose £32.5m transfer was supposed to symbolise the club's ambitions wants no further part in the revolution.

Fourteen months after breaking the English transfer record to join the club from Real Madrid, Robinho is now so unsettled he has informed his advisers he does not "want another day in Manchester". Mark Hughes, the City manager, described the revelation last night as "people making mischief" but, behind the scenes, he has known for a long time that Robinho is disaffected and, grudgingly, the club have started the search for a possible replacement. Angel Di María of Benfica has been identified among the leading candidates and has a £27m buyout clause in his contract.

The question now seems to be when, rather than if, Robinho leaves. Hughes is keen not to lose such a talented player in the middle of the season but, if the Brazilian has his way, he will move at the earliest opportunity.

That will be a major disappointment to a club of City's aspirations, with Hughes stating recently that they were "not in the business of selling our best players", but the manager may have contributed to Robinho's unhappiness by disbanding the small but influential group of Brazilian players that he regarded as cliquish and undermining his authority.

Elano Blumer, who was regarded as a troublemaker, was sold to Galatasaray in the summer while Jô was loaned to Everton and Glauber Berti also left the club. That, however, has left Robinho feeling isolated and not enjoying the experience of being in Manchester, a city he has struggled to embrace. His wife, Vivian, is also unhappy in England, neither of them having learned the language and both disliking the climate. Their problems even extend to moving house because of a dispute with their neighbours over them playing Brazilian music.

City's official position is that they have not spoken to Barcelona and have no intention to do so. Nonetheless, they do not consider Robinho indispensable when they have Craig Bellamy and Martin Petrov to play the same position on the left side of attack, and particularly when they know that the Brazilian is not fully committed to being a part of the club's future.

One idea is that a player-plus-cash exchange could be arranged that would see Yaya Touré join his brother Kolo at Eastlands, although the midfielder's agent, Dmitri Seluk, said that his client would go to a "more important club". In which case Barcelona would have to find in the region of £30m either in January or at the end of the season.

From City's perspective, however, it is not a question of finance, but of what it would say for their ability to handle players of Robinho's profile. Garry Cook, the executive chairman, said "categorically" there was no plan to sell the player and Hughes added: "I am quite clear and Robinho should be quite clear that his future is very much with City. There is no reason to think that will change any time soon. These stories do not originate from anyone from City."

Robinho, nonetheless, has made no secret of his desire to move to Barcelona, frequently speaking to the Spanish press about what he described his "dream" – the same word Cristiano Ronaldo used when talking about his intention to leave Manchester United for Real Madrid. Robinho's form since joining City last September has been exhilarating at times, but there have also been other periods when his attitude has come into question and there have also been various off-field issues.

He was arrested on suspicion of rape after an incident at a Leeds nightclub earlier this year and, though he was never charged, the possibility of a court case was hanging over him for five months – something, he feels, that contributed to his loss of form and that has influenced his views on life in England.

He has not established a strong relationship with City's management either, and there was a point last season when Hughes and his coaching staff were debating whether they should try to sell him anyway, the idea being that he could be used as the bait in an exchange for Franck Ribéry of Bayern Munich. Ribéry, however, was not tempted by the idea.