Roger Federer has revealed the key reason why he is always motivated to win more tennis titles even though he is nearing the end of his career, according to a report on the Express.

Federer said that it was his determination to keep working hard that has helped him to keep winning titles throughout his career.

The Switzerland international won his sixth Australian Open last month to take his total tally of Grand Slam titles to 20, which has resulted in many pundits and players hailing him as the best ever tennis player.

Michael Dodge/Getty Images Sport

However, Federer has kept himself grounded and continues to work hard. He now has the chance to create history this month as he can become the world’s oldest ever world number one.

He currently sits behind Spaniard Rafael Nadal but if Federer reaches the semi-final of the Rotterdam Open, then he will overtake him into first place.

Federer said:

I think, always wanting to improve as a player, you know, trying to find new ways to make it exciting for myself.

Playing on a big stage, honestly, that’s the fun part so that is very motivating in itself.

And then I can play for world number one or for titles, I mean, at the end of the day winning never gets boring, to be honest.

Federer will play his opening match of the Rotterdam Open today and is the favourite to lift the trophy after compatriot Stan Wawrinka fell to a shock defeat in the opening round.