The 33 year-old picked up a knee injury in training with Bundesliga side VfL Bochum earlier this week and the player, known as The Helicopter, is expected to be grounded for around five weeks.
Hashemian, who retired from the national team in June after Iran failed to qualify for the 2010 World Cup, has been struggling for playing time with the club and this setback means that he will not be ready for a return until October.
The striker’s contract ends next summer and it is not expected that it will be extended.