The 26-year-old player is a member of Cape Town City at the moment.
Patosi signed a six-year contract with Lokeren in May 2011 and returned to South Africa in June 2017 to join Cape Town City.
Esteghlal has completed signing of two new players in the recent days.
The Blues signed Omid Noorafkan on loan from Charleroi and Esmaël Gonçalves “Isma” from Pakhtakor Tashkent.
Esteghalal is preparing for the second half of the Iran Professional League (IPL) season.
The team is a favorite to win IPL title as the team sits fifth in the table, six points behind the leader Sepahan.
Esteghlal will start the IPL season second half with a match against Paykan on February 3.