Roger Federer will continue to trial a radical new racquet — whose 98-square-inch size will take some adjustment after playing for years with a model measuring 90 square inches — at the Swiss Open.

Federer, the top seed who has not played the high-altitude clay of Gstaad since winning the title in 2004, will continue his racket testing under competitive conditions.

He will face off on Thursday afternoon in the second round after a bye, playing the winner from long-time friend Marco Chiudinelli and German Daniel Brands, whom he needed three sets to beat a week ago in the Hamburg first round.

Federer said that he feels he is slowly getting used to his new racquet, which should provides him some additional power and a bigger hitting sweet spot, as he lifts his equipment to the level long used by his rivals.

But any decision on switching to the new weapon will not be taken in haste.

“So far, I’m happy with this change,” said Federer. “But I need lots of court time to know if switching will be a good decision.

“I haven’t yet decided on whether to use it in the US (he begins his pre-US Open campaign in a fortnight at the Montreal Masters). I still need to think it over.” But he added, “This racquet will probably change over the next few months, we will keep tinkering with it. I’ve tried a lot of models and this is the one I like the best. I’ll play Gstaad with it and then we can look ahead. The plan for now is to continue with this racquet.”

Federer was less interested in addressing reports that he might have been suffering with his occasionally-dodgy back during the Hamburg clay week.

“Honestly, last week was not optimal. I couldn’t play as free as I would have liked to do. But I don’t want to talk of this. I just want to make a good preparation and am doing everything to be ready for my first match.” On court, three Spaniards, including eighth seed Robert Bautista Agut, moved into the second round.

Agut beat Swiss wild card Henri Laaksonen 6-2, 6-3 as the Spanish winner ran his clay record in 2013 to 18-15. Daniel Gimeno-Traver beat Kenny De Schepper of France 6-4, 6-3 while Pablo Andujar defeated Romanian Victor Crivoi 6-1, 6-2 to end a five-match first-round loss streak before afternoon rain interrupted play.

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