According to Greek site, the officials of Olympiakos have reached final agreement with Ansarifard.
He featured in Iran's World Cup qualifier against Syria on Tuesday in Malaysia.
The Iranian international striker has already caught the eye of Dutch professional football club Feyenoord Rotterdam, Olympique de Marseille, PAOK and AEK.
Ansarifard’s contract will expire at the end of the season.
The international striker joined Greek Superleague club Panionios from Osasuna in 2015.