Zubar ended his three-and-a-half year stay at Wolves before the winter transfer window closed after signing for Ligue 1 side Ajaccio until the summer.
The 27-year-old says he had the option of moving back into the Premier League, but he plumped for Ajaccio because he had the chance to play at centre-half again.
"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."
However, despite not always playing in his favoured position at Wolves, the former Marseille defender confirmed he enjoyed his time in English football.
He added: "Defending is much appreciated in England. When I came, I saw all the effort made by the guys. At l'OM, I also include myself in this, we didn't do so much.
"Rooney, who maybe earns €15million, makes a sprint to go and score, and does an even bigger sprint to go back and defend.
"When I came, the coach saw me trying to make good gestures and passes during the first match. He immediately told me, 'I didn't sign you to play like Laurent Blanc. I don't want my central defenders to chest the ball or things like that'."