The Morocco international has been in talks with a move to Romania with CFR Cluj.
But club owner Ioan Varga has explained they've now pulled out of negotiations.
"Ziyech failed, he has a problem in his left knee that I was informed about," Varga told Prosport. "He's a very good guy, but I wouldn't risk that much money for a player who might have medical problems.
"I also studied him in the Galatasaray games, and he seemed to play with some fear.
"We have made the decision to withdraw from the talks. I'm sorry, because he's a special boy, but I don't want to risk it.
"He wanted 2.5 million euros a year, and I wouldn't have given this money to a player we risked not being able to use.
"I wish him to be healthy, and to be able to play for another team. We will look for another player who is healthy, and we are sure that he can help us."