Federer relaxed about No. 1 ranking quest in Miami

Roger Federer needs to advance to the quarter-finals in the ATP Miami Open to hold on to his number one ranking, or face being supplanted by old rival Rafael Nadal. (Photo: AFP/Matthew Stockman)

The 36-year-old Swiss star needs to advance to the quarter-finals in Florida to hold on to his number one ranking, or face being supplanted by old rival Rafael Nadal in top spot.

However Federer, who was beaten by Juan Martin Del Potro in Sunday's Indian Wells final, said he is not attaching too much importance to hanging on to his ranking.

"The number one ranking is in my head a little bit, but no more than that," Federer said. "It's a mini-goal. It would be nice to stay there but it's no more important than that.

"You have to win matches to go far here. Going far enough to stay number one, it helps my motivation to have a goal. But even if I don't manage it, it's not the end of the world."

Federer will launch his Miami campaign on Saturday against a qualifier.

Federer, winner of an incredible 20 Grand Slam singles titles, meanwhile spoke admiringly of Del Potro's rehabilitation into the tennis circuit's winners circle following a career-threatening wrist injury.

"I can only look from far away and think, 'I wonder how it was for him.' Hard to imagine how - most important about having had surgeries, I guess, and being injured is the doubts you have. Are you ever going to come back? And overcoming that fear and gaining confidence again," Federer said.

"It's such a nice story because he finally did it, but he had to do it the hard way, put himself out there, knowing he was not going to win all the matches he was going to play.

"It's tough to do that, you know. That deserves a lot of respect, in my opinion, especially knowing what level he can achieve as a player."

Federer said he had already moved on from Sunday's loss to Del Potro in Indian Wells, saying he was due a loss after a successful 2017.

"Didn't take me a whole lot of time to get over it, to be honest, because I felt like it could have gone either way," Federer said.

"Unfortunately I wasn't on the winner's side because maybe I have had enough luck throughout the last 14 months on my side of the court, so it's OK to lose some.

"I felt that also Juan Martin had to earn it. He had to play good to get it. Then you kind of move on with it."