Partizan Belgrade manager Avram Grant claims Iranian side Sepahan Isfahan have pulled out of a friendly with his club because he is Israeli.
Partizan, who appointed Grant as their new manager last month, had been due to play the Iranians on Friday in Turkey, but their opponents, who hail from an Islamic republic, have pulled out of the match.
In an explanation posted on Partizan's official website, the former Chelsea, Portsmouth and West Ham United manager said he had been told "unofficially" that the match had been cancelled because he was Israeli, and called the decision "shameful".
"I never mixed politics with sports," Grant said. "I had worked with many [Muslims] while I was in England, and I made friends with many of them."
Partizan say they had to switch their usual winter preparations from Dubai, in the United Arab Emirates, to the Turkish city of Antalya because of Grant's Israeli citizenship.