Michael Schumacher was on Monday forced to defend his reputation as he faced up to the least attractive aspect of his Formula One comeback.

Schumacher has never enjoyed his media duties, and in pondering whether to return he must have questioned whether he again wanted to face the intrusion.

That is despite the fact he knew he was ready to return, mentally and physically, after more than three years away.

So it perhaps came as no surprise that on the day of his official presentation as a Mercedes GP driver, his past should be drawn into question.

After all, despite his unprecedented success there remain stains on his character, such as his infamous collisions with Damon Hill and Jacques Villeneuve as he fought for the world championship in 1994 and 1997 respectively.

There was his victory in the 2002 Austrian Grand Prix when then team-mate Rubens Barrichello was ordered to pull over to allow the now 41-year-old by.

And, of course, there was the deliberate parking of his Ferrari at La Rascasse in qualifying for the Monaco Grand Prix as he attempted to thwart then title rival Fernando Alonso.

When asked whether his return was an opening to show he could win in the right way, Schumacher's response positively bristled with indignation.

The German sarcastically replied: "Ninety-one victories, seven titles, you win only in a bad way. Absolutely. Yeah, you're right, I need to prove (myself) now."

When it was put to Schumacher the initial question referred to the manner he won, and not what he won, Schumacher caustically remarked: "Yeah, I know.

"I did win all this in the manner in which you are trying to ask questions."

In a more serious tone, he added: "Let's be sensible and think about the reality, and look forward to what we might all face, learn and enjoy together. That's what I'm looking for."

There is no doubting Schumacher's status in F1 history, although in returning now, he has arguably never faced such a challenge as the one he is likely to encounter.

It is 11 years since there were four world champions on the grid as there will be this year in Schumacher, Lewis Hamilton, Jenson Button and Alonso.

But back in 1999 when Schumacher, Mika Hakkinen, Hill and Villeneuve were all in the field, only the former two were in competitive machinery.

When you throw in close friend Felipe Massa at Ferrari and young pretender Sebastian Vettel at Red Bull, even team-mate Nico Rosberg, Schumacher's battle for an eighth crown is an uphill one.

"Compared to the past when there was one team able to compete (McLaren with Ferrari), the way it is now there are two or three teams," suggested Schumacher.

"Last year was probably an exception, and it might be again, but in all honesty it doesn't really matter.

"You are there to win, and against whoever it is you have to look out for. It doesn't matter whether they are young or experienced.

"When you're in the car you don't look at how old your opponent is or who it is, you just look at how you can be better than whoever it is."

Schumacher may have been away for three years, but time has far from dulled his sense of self-belief as he is convinced he can extend his record of world titles.

"We have everything it takes (at Mercedes) to be world champion again, but it's one thing to have all the ingredients, it's another to conjure a result," assessed Schumacher.

"But with the experience Ross has, and with what he did last year, and with Mercedes' know-how and the quality they have, I'm sorry, but there is only one target (the title)."

Brawn recently remarked that of the four competing world champions this year, he felt the German had the best chance of adding to his success.

That is despite Schumacher's hiatus, and the fact he has not competitively driven an F1 car since October 2006.

Explaining his reasoning, Brawn said: "What I've seen with Michael is that he has been refreshed by his break.

"We've seen today he is looking incredibly fit, and far younger than his 41 years.

"So I don't think the physical side is a problem, and he has shown amazing commitment and dedication already by working hard with the engineers.

"I don't think the talent disappears, and even if it eases off a little, you've the huge experience he has to compensate.

"He wouldn't do this if he wasn't convinced he could do the job, and I'm convinced he can do the job.

"I've already seen amazing commitment, and it reminded me of the old Michael Schumacher."