The 26-year-old joined the Greens from Russian outfit Rubin Kazan in a three-year deal last year but the club’s financial challenges have all but cut short his stay.
The former Villarreal man spent the second half of last season out on loan at Spanish club Granada.
“Before I joined them [Panathinaikos], I spoke to Mike [Michael Essien] who told me the club was having some financial problems,” Wakaso was quoted as saying by FMG.
“But the club officials assured me I would have all what I’m entitled to and that was why I signed for them.
“Initially, things were okay until they started skipping payment of my salary and then I had to start paying my own rent when it was the club that was supposed to pay.
“It was becoming too much and that is why I had to leave on loan and I don’t think I will go back.
“The contract will be terminated and I will be joining a new club soon."
Reports say Wakaso is likely to join a team in England, with Stoke City, Aston Villa and Reading as possible destinations.