Seven times Formula One world champion Michael Schumacher refuses to divulge his personal goals on his return to the circuit after three years in retirement as he fears they could come back to bite him.

The German's first race back yielded a sixth place finish at the season-opener in Bahrain, one behind fellow German and Mercedes team mate Nico Rosberg, a performance the 41-year-old said he was satisfied with on Thursday.

‘This is the first race in the beginning of a new challenge to me so I'm quite relaxed by that,’ Schumacher told reporters at Albert Park circuit ahead of Sunday's Australian Grand Prix.

‘(Rosberg's) a very good and fast driver so I don't think I need to be ashamed of where I have been in Bahrain.’

When asked to elaborate on his aims for the season, Schumacher replied: ‘Why do you want to fix me on something that you can come back by the end and tell me 'ah, you were much worse than you said and much later, da da da...'?’

‘Keep trying but I don't go with it,’ he smiled.

‘I think it's fair enough to be judged on results, absolutely, but I don't feel I need to give guidelines or references, when and how I will achieve them.’

While Schumacher's fellow drivers welcomed him back to the fold as a positive for the sport they have expressed concerns that the German might tarnish his legacy if Mercedes was unable to perform against the likes of Red Bull and Ferrari.

‘I'm mainly here for the enjoyment but at the same time, I'm not only here for being last, I want to win. That's natural,’ Schumacher continued.

‘The joy is much better and higher if you be successful... Maybe I'm a little bit addicted to challenge. That's true.’