The 27-year-old player will undergo a medical to complete his move to the Greek team.
Haji Safi is set to team up with fellow countryman Masoud Shojaei at Panionios.
Haji Safi started his career in Zob Ahan in 2000 and left the club in 2006 and has played in Sepahan, Tractor Sazi and FSV Frankfurt.
He has represented Iran at the 2011 AFC Asian Cup, 2014 FIFA World Cup and the 2015 AFC Asian Cup, in addition to Sepahan at the 2007 FIFA Club World Cup.
He has scored six goals in 82 caps for Iran.