Grant took over the Serbian champions last month, and this is the second such incident already to affect the team.
Last month Partizan claimed that they were forced to conduct winter training in Antalya instead of Dubai because Grant, as an Israeli citizen, was barred from entry to the Emirate.
The Serbian team's clash with Sepahan was due to take place on Friday (February 25), but on their website Partizan say that their opponents have pulled out of the game.
They cite “tense relations between Iran and Israel” as the explanation for their opponents' withdrawal.
Grant was incensed, and the former Chelsea coach said: “I'm disappointed.
“Unofficially, I've been told Iranians do not want any kind of contact due to me being Israeli.
“I never mixed politics with sport.
“I worked with many Iranians while in England and have friends among them.”
The spat comes at a time of extreme tension between Israel and Iran over the latter's alleged development of nuclear weapons, and it is expected that the Israelis, possibly with American and/or covert Saudi Arabian support, will launch an air raid in the coming months to take out their nuclear facilities.
Iran, like most states in the Middle East, do not recognise Israel, whilst the Jewish tate accuse the hardline Iranian regime of sponsoring terrorist groups in the Gaza Strip and Lebanon.
Iran have long refused to allow its sports people to take on Israeli athletes in sporting competitions.
Swimmer Mohammed Alirezaei withdrew from competing against Israeli opponent Gal Nevo during last summer's World Aquatics Championships, and in 2004, an Iranian judoka, Arash Miresmaeili, forfeited his chance of a medal at the Athens Olympic Games when he withdrew from competition against Ehud Vaks.