Azmoun, who has scored 57 goals in 91 internationals, was the most notable absence from a 35-man squad named by coach Amir Ghalenoei on Friday for friendlies against Nigeria and Costa Rica in the Turkish city of Antalya.
Azmoun, who plays his club football in the United Arab Emirates for Shabab Al-Ahli, upset the Iranian authorities this week by posting a picture on his Instagram feed of a meeting with Dubai's ruler Mohammed bin Rashid Al Maktoum.
Iran has launched rocket and drone attacks on the UAE following air strikes by the United States and Israel, which killed the country's Supreme Leader Ayatollah Ali Khamenei.
A report by the Fars News Agency, which has links to the hardline Islamic Revolutionary Guard Corps, cited "an informed source within the national team" as saying Azmoun had been expelled from the team.
There was no response to a request for comment on Azmoun's status from the Football Federation of the Islamic Republic of Iran (FFIRI).
Iran's participation in the World Cup is under a cloud because of the ongoing conflict with the United States, which is co-hosting the June 11-July 19 tournament with Mexico and Canada.
The squad also included a first call-up for German-born striker Dennis Eckert, who plays in Belgium for Standard Liege but has Iranian ancestry through his father.
