ESTORIL, Portugal (AFP) - Roger Federer will test the waters starting on Tuesday at the Estoril Open with the hopes that a coaching trial with Spaniard Jose Higueras could translate into long-term clay-court success.

The Swiss confirmed on Monday that the 55-year-old former great who has guided Pete Sampras, Jim Courier and Michael Chang among others will be a great aid in polishing his dirt game.

The world number one who is seeking his first title of 2008 after dealing with the mononucleosis virus at the start of the season, is playing at a non-Masters Series or Grand Slam event for the first time since winning Munich five years ago.

Federer and Higueras have worked together for three days, with the Swiss optimistic that the new relationship will play immediate dividends.

"Jose is gonna do this week and we will see how it goes from here," said the 12-time Grand Slam winner who refuses to characterise his search for a Roland Garros title as his main objective.

"It's just all starting, I'm happy he's here," said the 26-year-old who begins play on Tuesday against longtime friend Olivier Rochus of Belgium in the first round.

Federer, who parted with Australian Tony Roche last May said that he considered the possibility of hooking up with Higueras during his American tournament swing last month, where he reached an Indian Wells semi-final and played the Miami quarter-finals with a loss to Andy Roddick.

"I've been thinking about a coach for a long time, who would be the right guy," said the Swiss. "There here are not too many of them out there.

"Once I had Jose in my mind I asked if he was interested. He's quite flexible and came over. It all happened when I was in the States, I took the decision there."

Federer displayed his trademark cool demeanour when faced with a season where he gone through the first quarter without reaching a final.

"I was sick as a dog at the start, I'm happy I was able to bounce back.

"My first goal was to feel better again, get over the sickness.

"We're now in a different part of the season, it's back to zero for everybody.

"I disagree with those who say I'm playing bad. I'm definitely not playing bad. I'm on the verge of playing great again, that's what I'm looking at."

Federer said that his work with Higueras has more than just winning in Paris as a focus.

"You try to improve as a player, You need people around who make you better, fitter and stronger. Those guys work hard to make you play better.

"If that happens at the French Open, that's the perfect scenario. But I think it is the wrong approach to concentrate only on Paris.

"We'll have to see how this arrangement goes. It's pretty open at the moment.

"It's a similar arrangement like it was with Tony Roche - but first we have to get through this week and see how it goes from there."