Manchester City last night faced the double ignominy of being forced to halve the fine handed out to Carlos Tevez and to allow him further games for the club, if he is not sold in January.

The Professional Footballers' Association chief executive Gordon Taylor's unexpected declaration yesterday that Tevez had not been guilty of refusing to play at Bayern Munich last month and that his four-week fine was excessive infuriated City, who had needed PFA consent to fine the player more than two weeks' wages.

The club's consultations with Taylor began the day after the Bayern match and left them with the clear impression that the PFA agreed that an extension of the standard two-week fine, requiring approval, was appropriate in this case. But Taylor has performed what the club view as a U-turn – the result of "an apparent conflict of interest" on the 66-year-old's part, City said last night – and now concludes that the club's accusation of a refusal to play is unfounded and the fine unreasonable.

With no available challenge to the PFA decision, City reluctantly accepted last night that the maximum two-week fine provided for in standard player contracts would be applied: £396,000 in Tevez's case. "Carlos Tevez has been personally represented throughout by the PFA chief executive, on whose considerations the Club has been informed that the PFA has made its decision," was an indignant City's response. Taylor, who was Tevez's PFA representative at last Friday's hearing, may also have heartened the Tevez camp when it decides on whether to lodge a defamation action against City manager Roberto Mancini for twice declaring in Munich that the 27-year-old had refused to play.

City's attempts to maintain a hard line against Tevez are further undermined by Fifa legislation which means they must play the Argentine in 10 per cent of their games this season or risk giving him the right to terminate his contract and walk away.

The club indicated in the strongest terms possible on Tuesday evening that their Abu Dhabi owners consider it a matter of principle that Tevez should not be allowed to leave for less than last summer's £40m asking price, making a January sale unlikely. But Article 15 of Fifa's Regulations on the Status & Transfer of Players stipulates that the striker is entitled to terminate his contract under "sporting just cause" next summer if he has been on the field for less than ten per cent of City's total game time by then. The Tevez camp are aware of the case of Goran Pandev, the Macedonian forward forced out of the Lazio squad by club president, Claudio Lotito, in the summer of 2009, after angering Lotito by indicating a desire to leave the club. In a case with echoes of Tevez, Lotito rejected a €13m offer for Pandev from Zenit St Petersburg as too low and within months Pandev filed for termination of his contract. Italian football's governing body, the Lega Calcio, ordered Lazio to release him and pay €170,000 for emotional distress.

British sports law specialists believe that Tevez will have a good chance of successfully invoking Article 15, in a case which may go to the Court of Arbitration for Sport, if City reject low offers in January and keep him out of the side until next summer. The club have rejected Corinthians' latest talk of an £18m deal. "Tevez would have good grounds to invoke article 15," Daniel Geey, solicitor at Field Fisher Waterhouse, said yesterday. "It would be the ultimate way to score over City. The club would not secure a transfer fee, his contract would be terminated and he would be free to sign somewhere else and get a signing on bonus."

But it is Taylor's statement which left the club most damaged last night. The club's attempts to prove Tevez refused to play, rather than warm-up, an offence he admits, had already been undermined by an apparent disparity between the disciplinary hearing verdict published on the club website late on Tuesday, and a letter to Tevez explaining his conviction. The website cited "an obligation to participate in any matches in which the player is selected to play for the club" as one of five contract breaches. The letter sent by City to the player's lawyers cites only a failure "to resume warming up with a view to playing in the match."