The pay-per-view event will be held at the Telekon Center at the OAKA Olympic Complex in Athens.

Mayweather, 49, retired from boxing in 2017 with a perfect 50-0 record.

He has appeared in multiple exhibition bouts since then, but an exhibition announced late last year against former heavyweight world champion Mike Tyson has never materialized and plans for a official rematch with Philippines ring icon Manny Pacquiao — announced by Netflix for September — have also run into trouble.

That bout, announced for the Sphere in Las Vegas, would have been a rematch of the highest-grossing clash in boxing history.

But after Mayweather said the fight would be an exhibition only, Pacquiao insisted he had signed a contract for an official bout.

Whatever the fate of that contest, it won’t take place at the Sphere on Sept 19 as originally announced with the venue now set to host a concert by the Eagles on that date.

Mayweather said in a statement on Thursday that the clash with Zambidis “is an opportunity for me to sharpen my skills for what’s to come this year.”

Zambidis, 45, is an 18-time world champion best known for his career in K-1 MAX.