Mika Hakkinen has taken a swipe at former rival Michael Schumacher, saying that he is now a "tragic ex-hero" and that he should retire immediately.

Hakkinen enjoyed several memorable title clashes with arch-rival Schumacher, notably in 1998 and 2000. But after a disastrous return to Formula one that saw young team-mate Nico Rosberg accrue nearly twice as many points, Hakkinen says it is time for the German to call it a day.

"Michael is for me now a tragic ex-hero," Hakkinen told Munich newspaper TZ. "I ask myself why on earth he got back into the cockpit. There is the most successful man in motor sport driving down in the pack and making a ridiculous mistake in Abu Dhabi that almost cost him his life."

Schumacher's already disappointing season could have ended in far worse circumstances after a spin on the opening lap saw Tonio Liuzzi's Force India launch into his Mercedes, the nosecone and front wing narrowly missing his head.

"What a tragedy this would have been for the Germans - and on the day of Vettel's triumph. What has the man who has won more than anyone else still to prove? In my view, he is dismantling his own legacy bit by bit. And I see it making no difference whether it is for technical reasons or because he can no longer keep up with the boys."

Like Schumacher, Hakkinen himself contemplated a return for Formula One after his retirement before eventually taking a drive in DTM. But he warned that today's young guns are no respecters of reputation.

"After three years I returned to the cockpit myself -- for Mercedes in the DTM. And I also had to recognise that even as a Formula One world champion, there are no gifts for the older ones.

"I won only three times more. You can neither stop the wheel of time, nor turn it back. Personally, we were never close friends because he always came across, to me anyway, a little bit too arrogant."