Zubar quit Wolves for Ajaccio in January.
"I broke my contract with Wolves, where I had five months left, and signed for Ajaccio until the end of the season," Zubar told L'Equipe.
"The idea was a new challenge. Above all, I wanted to find my right position again as a central defender.
"In England, I was always played as a right full-back. This winter I had opportunities at Wigan or Southampton, but not as a central defender."