The PFA fought Tevez's corner to get initial sanctions reduced, but chief executive Gordon Taylor is uncertain what now lies in store for the former City captain.
"I have been accused at times of defending the indefensible," Taylor said.
"It is very difficult to now be in a situation where we put our heads on the block.
"I do feel very disappointed to say the least that when I was hoping things could move on, it has gone into reverse and now he is left in a position that becomes very vulnerable.
"The lad is digging himself a hole and it is going deeper. It is a worry to me how we can now get out of this.
"He is a human being and a top-quality footballer, but his actions are not what we could possibly recommend to any other player in the game.
"It goes to the heart of the contract and that could be gross misconduct in anybody's language.
"I don't want to predetermine, but I am very concerned because it is a serious situation and one that the PFA are not happy about."