The accusations flying around appear to be without substance, but Rafael Nadal should have other things on his mind than having to deny a report in France's Journal du Dimanche. The unsigned report said the Spaniard's name was on a list of athletes implicated in raids last month by Spanish authorities on laboratories involved in doping.

Evidence gathered in those raids was used to expel several cyclists from the Tour de France, including the marquee names of Jan Ullrich and Ivan Basso.

On Monday the Spanish government agency for sport, El Consejo Superior de Deportes, released a statement denying any tennis players were implicated. Still, Nadal was drawn in and just two days before meeting Finland's Jarkko Nieminen in his first Wimbledon quarter-final, the 20-year-old, breaking from imperfect English to make his point clearly in Spanish, had to set the record straight.

"I've never taken anything in my life and I never will," said Nadal. "People who write lies about other people are bad people."

Meanwhile, as the courts remain baked and the ball bounces high, Wimbledon is shaping up nicely for the unbeatable claycourt player as people continue to look at just him and the world number one, Roger Federer, as likely opponents in the final despite there being two rounds to play.

Nieminen, who lost to Nadal in their two previous meetings, most recently in Barcelona earlier this year, is in his second Grand Slam quarter-final. He's here at the expense of the Americanised Russian Dmitry Tursunov, who caused something of a stir when he hit a ball at umpire Fergus Murphy during Monday's match before roundly abusing the Irishman.

Either Nadal or Nieminen must also meet the winner of Lleyton Hewitt's match with Marcos Baghdatis, and while the Cypriot is less well known, Hewitt's passage against a man he has never played is not a foregone conclusion.

Baghdatis made it to the final of this year's Australian Open, while Hewitt is just coming out of a slump in which he hadn't won a title since January 2005 until the Queens event before Wimbledon.

"He struggled (in the) first round against Alan Mackin and he beats Murray in straight sets," observed Hewitt of Baghdatis.

"Everyone has been put on notice of the kind of flair and talent he possesses playing at his best."

On the top side allegations are also flying. Federer is being accused of being unbeatable, though his meeting with Croatia's Mario Ancic for the fifth time in his career promises to bring out the best in the champion.

Importantly, Ancic was the last man to beat Federer at Wimbledon - in the first round of the 2002 championship. Since then the Swiss player has not lost to anyone on grass, which equates to 45 consecutive wins. A record, naturally.

Nor has Federer had to reach into a fourth set to get him this far, and only one of those straight-set victories needed a tiebreak.

Ancic's inherent talent is undeniable, but be sure he just wishes he had been one rung lower in the draw and facing either the Czech Radek Stepanek or Sweden's Jonas Björkman, who contest the other quarter-final.

It's the least-likely pairing to have reached this point, given that David Nalbandian, ranked three in the world, and James Blake, ranked seven, were both in this half.

Stepanek has the higher ranking but Bjorkman leads the Czech 3-0 in career meetings, none of them on grass.