Casey Stoner has once again defended his decision to skip three races during the middle of the 2009 MotoGP season to shake off mystery fatigue problems - and insists the exhaustion is now behind him.

In contrast to the pale and pasty figure that frequently faded backwards during the five races before his mid-season break, the 2007 world champion looked invigorated on his way to a strong second position on his Estoril comeback.

It marked Stoner's best result since victory at round five at Mugello, the last event before he was struck down by sickness at Catalunya, and was hailed as proof that stopping had been the right thing to do.

But the inability of doctors to give a clear-cut explanation for Stoner's fatigue problems led fellow Australian world champion Wayne Gardner to suggest, even after Estoril, that Stoner 'needed to come up with some answers' to explain his absence.

Results of a medical report had named 'low blood pressure levels and a lack of sodium' as the 'main cause of the physical problems', but also listed overtraining and the after-effects of past injuries and surgeries.

Regardless of the specific cause, Stoner insists it's now under control and that without the break he wouldn't be in with a chance of fighting for his third home victory in a row this weekend at Phillip Island.

“If we continued racing through the season and had not gone back to Australia to figure out what was wrong, then coming to this race it would have been another impossible task even being close to victory,” stated Stoner, an 18 time MotoGP race winner for Ducati.

“Throughout the race in Portugal I could have held a higher pace, not gone faster, but held the pace for a lot longer. It wasn't necessary because we had second in the bag, but it was just such a good feeling. We haven't had that in such a long time.

“When we think about it I've had this problem for a lot longer than we thought. It just didn't show until a hot race like Catalunya and from then on we just struggled. It's very nice to sort it out and come here with a new enthusiasm for racing and getting back out there and enjoying it.”

So was there any repeat of the tiredness at Estoril?