Swiss star Roger Federer was not worried by his second round defeat to Ernests Gulbis at the ATP Rome Masters on Tuesday.

The world number one suffered a shock 2-6, 6-1, 7-5 defeat to the 40th ranked 21-year-old Latvian.

But the winner of 16 grand slam titles seemed unperturbed when talking about his match afterwards and even suggested that such a defeat has good side.

"It is easier to take because I'm used to winning so much so that sometimes when you get a loss ... you can't always win and sometimes it takes a loss to wake up and sort of shake your mind up and think about how you're going to approach next week," he said.

"Because sometimes when you win it's just too easy and too simple. When you lose, you actually realize how tough it is to dominate this knock-out system we have in tennis which is brutal."

Federer will play in Estoril next week and then Madrid after that as he want to build up some clay form ahead of the French Open.

"I'm not too worried, I'm more curious to see how next week goes. If you lose early you can't wait for the next tournament to come around. That's the way I feel."

Federer paid tribute to his young conqueror and said it was no surprise to see Gulbis doing well.

"This is the second time I have played him. I played him in Qatar and won in three sets. I'd always thought he had great potential when I watched him play, he has immense power on both sides."