Love for tennis can take Federer beyond 20 Grand Slam titles: Annacone

London - Tennis ace Roger Federer can increase his number of Grand Slam titles beyond the 20-mark as long as he stays in love with the game, according to his coach Paul Annacone.

Federer won his 16th major title at last year's Australian Open, but since then he has dropped to No.2 in the world, behind Rafael Nadal.

But the appointment of Annacone to the Federer camp last September is a sign he is not yet ready to hand over total control to the Spaniard, The Daily express reports.

Last week he beat Nadal in Doha on his way to the 67th title of his career.

"It has been a great ride so far. Every time I wake up I kind of have to pinch myself a bit. I've been pretty fortunate in my career, because I've had the best jobs you can have in terms of coaching at the top level, being around Pete for eight years, Tim for four and am now lucky enough to be working with Roger," said Annacone.

"In today's game, guys are so good at the back of the court. The biggest thing that Roger has going for him is that he can do so many things at such a high level. He can win every tournament he plays. There are not many guys you can say that about," said Annacone.

"So if he can stay healthy and happy and eager, I don't know what the end number would be, but is 20 realistic? Sure, why not?

"One of the most amazing things about Roger is he so loves it still, it's not a grind to train; the energy he has is incredible. These guys, when they win this much, they've earned the right to say when they've had enough - and I don't see that in sight," he said.