The 32-year-old - a member of the 2004 Olympic gold medal winning side - left United in 2007 for Real Madrid after Manchester manager Sir Alex Ferguson replaced him at left back with Patrice Evra and then refused to sell him to bitter Premier League rivals Liverpool.

"I am very sorry that I left," said Heinze, who was voted United supporters' player of the year for the 2004/05 season.

"Sadly things happened in the final few months there that I regret.

"But everyone has his character, like Sir Alex Ferguson and myself.

"We are two strong characters. The club, though, gave me a lot, and the supporters were at my side from day one.

"But there are things that happens in one's life...," added Heinze, capped over 70 times and twice a Copa America finalist.

Heinze, who has won three league titles during his 12 years in Europe: the Premier League with United in 2007, the Spanish with Real Madrid in 2008 and last year the French one with Marseille, said overall he retained happy memories of his three year spell at United.

"I spent three formidable years at Manchester, and have many happy memories," said Heinze, who began his European career with unfashionable Spanish outfit Real Valladolid before joining French side Paris Saint Germain in 2001.

"Those were very beautiful moments at a great club.

"I don't think things are very different today, because the same person who is in charge and who created the philosophy, the daily routine, and the club's message."

Despite the sour ending to their working relationship Heinze said he still had much to thank Ferguson for.

"Alex Ferguson gave me a lot. I arrived there aged 26, and he imbued in me the winning mentality, and under the best possible conditions.

"After all that if you played badly it was your fault!"

Heinze, a member of the 2006 and 2010 World Cup squads which went out both times in the quarter-finals, said that although Marseille were missing several first team players they could still put up a good showing against United.

"We are men just like them, with two legs and two arms! Of course there is a lot of quality running through our opponents, but it is vital we play with 100percent commitment, give our all, and we will have nothing to reproach ourselves for."