Gstaad - Roger Federer begins his quest for the title at the Swiss Open on Thursday inspired by the fighting spirit shown over the years by Australian contemporary Lleyton Hewitt.
The fifth-ranked Swiss who holds the record of 17 grand slam singles titles but has claimed just one trophy of any kind (Halle) in 2013, will start on Thursday in the second round against Daniel Brands, the German who took him to three sets last week on clay in Hamburg.
The 31-year-old Federer, who grew up in tennis with Hewitt, 32, told Swiss media that his motivation remains as strong as it always was, with his confidence high despite his lowest ranking in a decade.
"Lleyton Hewitt is a good example for me," he told Zurich's NZZ am Sonntag. "The ranking could be 170th, 20th or 5th - it's fun just to play."
Hewitt, ranked 64th, has been denying the years in recent seasons after his comeback from multiple foot surgeries. The Australian has reached the quarter-finals in Atlanta a fortnight after playing a grass final in Newport.
Federer added: "My motivation is at the top. If I got to the point where I'd had enough of the travel and training then I would ask serious questions. But that's not the case now.
"There comes a time when the ranking is not so important. Quite honestly, I don't even know exactly what my current ranking. 4th? 5th? 3rd? It doesn't matter to me so much.
"After Wimbledon (second-round loss to Sergiy Stakhovsky), I was burning to play."
The Swiss who looks consistently at the big picture in his career, said that he has dealt with doubts and harsh critiques before: "I have no problem with criticism, but I expect us to be honest," he told NZZ.
"This situation is not new for me. In 2009 and 2010 already, people said: 'He's won everything, now it's finished.' The more people that comment, the more likely that someone will be talking nonsense."
Federer will be looking for his 10th victory at Gstaad and his 31st of the season on clay when he plays Brands.