The 27-year-old returned to Argentina on Tuesday despite being refused permission to return to his homeland by the club, and the striker never showed up for training on Wednesday morning.
Taylor personally represented the forward to successfully help get his fine for refusing to play for the Blues in the Champions League halved, and the PFA chief criticised the former Manchester United man for his latest actions.
He told BBC Sport: “He's in danger of burning bridges rather than reconciliation.”
Afterwards, in an interview with Sky Sports News, Taylor said: “To say the least, I am very disappointed and extremely concerned now.
“To go out to Argentina when – as I have been informed – he was clearly told not to because [City] needed to work on his fitness, and to blatantly ignore that instruction starts to affect any chance of any reconciliation now.
“The whole relationship between clubs and players is one where there has to be clear understanding of what is to be expected and what is not expected.
“From that point of view, he is making it virtually impossible to have reconciliation and leaving himself very vulnerable to strong action by the club.
“If he is determined to leave the club, which may well be apparent, then his money value is being diminished by his actions and can affect another club's interest.
“As such, he could be held responsible for that, so it is getting to be a situation that I am not at all happy about.
“Neither are the club of course, and it is one that we will have to deal with.”
Tevez has been at odds with Manchester City for a while now after declaring he wanted a transfer last winter, but for a while the relationship between him and the club looked placid.
Over the summer, however, the Argentine claimed he would never return to Manchester and tried to force a move away.
Brazilian side Corinthians showed the most interest in the want-away striker but a deal could not be agreed upon and Tevez looked set to stay at the Etihad Stadium as the transfer deadline day passed.
The saga stepped up a notch when the forward refused to come off the bench for manager Roberto Mancini during their Champions League loss at Bayern Munich.
After the game, the Italian coach said he wanted the attacker “out of the club” because of his actions but has since publicly retracted his comments and accepted it is possible that Tevez has a future at City.
He was originally fined four-week’s wages by the club at a tribunal but an appeal supported by Taylor and the PFA brought the fine down to two-week’s wages, a move which reportedly incensed the Eastlands hierarchy.
The former West Ham United striker, who signed for City from their local rivals United in 2009, has not played for the Blues since September in a 2-0 win over Birmingham City in the League Cup.
Paul McCarthy, a spokesman for the Argentina international, claimed the forward would be back for training on Wednesday despite his departure to South America.
Many players are away on international duty at the moment but Tevez was not selected in the squad for his country’s 2014 World Cup qualification games against Bolivia and Colombia.