These are trying times. Players are beginning to crack under the water torture. Yesterday the pent-up frustration spilled from the court into the post-match press conference. As world number two Rafael Nadal finally finished his fourth-round match five days after it began, his prickly relationship with Robin Soderling continued unabated.

Both players were coy enough after the five-set match ended 6-4, 6-4, 6-7, 4-6, 7-5 in the Spaniard's favour but there was little doubting the hostility between them. The behaviour of Soderling throughout gave the impression that he was lampooning Nadal.

The Swede mimicked Nadal's stalling tactics, did not show the traditional and perfunctory courtesy when the second seed fell into the net, wouldn't apologise for a ball hitting the net and barely acknowledged the three-times French Open champion's offer of a handshake when the match came to an end.

It is far from being the first time players have kicked up a racket.

A few years ago, the former drug cheat Juan Ignacio Chela spat in front of Lleyton Hewitt's courtside chair, inciting a locker-room brouhaha between the two players' support groups.

Hewitt became involved in a spat with David Nalbandian, when the two made contact at a changeover during the Australian Open. And in Serena Williams's match against Justin Henin yesterday on Centre Court, Williams won her first point with a drive into the Belgian's body. No love lost there.

"He's a strange guy," said Nadal. "I've said hello to him about seven times and he never replied once. When I fell down at the net he never even bothered to see how I was."

Soderling was defensive when Nadal's criticism was levelled at him. At a disadvantage because the world's media were also watching, he did have some explaining to do.

"It was a really tough match. That's how tough matches are," said the Swedish player. "I mean I could say the same. I could talk s*** about a lot of people but I won't do that.

"He must have been in his complaining mood today. If my opponent gets a lucky shot and he doesn't say I'm sorry, I don't care. For me it's okay. Why should I say I'm sorry when it's the happiest moment of my life. It's just bull***."

Soderling, who was trying to reach the last 16 for the first time in his career, also defended picking at his shorts in the way Nadal often does before serving. He began doing it at the beginning of the fifth set.

"It was more a fun thing," offered Soderling. "I had to wait for him at the start of the fifth set. I had to wait for him, I mean more than 200 times. Every point I had to wait. He had to wait for me one time. He's shaking his head doing these things . . . maybe I shouldn't have done it."

Andy Roddick, who took just three sets to beat the Frenchman Paul Henry Mathieu 6-2, 7-5, 7-6 and set up a meeting with another Frenchman, Richard Gasquet, in the quarter-final, would not be drawn into the issue of Nadal's stalling tactics.

"I don't know," said the third seed. "It hasn't bothered me when I faced him. It's been brought up before but it doesn't bother me when we play."

Nadal is expected to face Roger Federer in the final, though given the way the bottom half of the draw has been delayed as well as the Swiss player's bye to the quarter-finals, it means he rests while the others spend endless hours in the locker-room.

If Nadal makes the final he will have played every day since last Saturday, while Federer's last match was against Marat Safin last Friday evening.

But the hiatus could be a double-edged sword. While the Swiss number one has practised throughout, he will not go into his match today against Juan Carlos Ferrero as sharp as he would have been had he been playing.

Federer also missed the pre-Wimbledon Halle tournament, meaning the champion's entire grass season to date has been the three matches against 86th-ranked Teimuraz Gabashville in the first round, 56th-ranked Juan Del Potro in the second round and 24th-ranked Safin.

"Yeah, there's no question he's probably not going to be as sharp coming off a five-day lay-off (as if) playing every day," observed Roddick.

"But fortunately for him that five-day lay-off came at the best possible time. It's not like it's been sunny. We've all been getting practice in. We've been stuck in a locker-room nine hours a day and he's been chilling out."

Serbia's Novak Djokovic, at 20 the youngest player left in the draw, advanced against Nicolas Kiefer 7-6, 6-7, 6-2, 7-6.