Soderling's belly as dodgy as his record with Federer

Facing Roger Federer on grass is usually a daunting enough prospect but lining up against the Swiss with a dodgy stomach could make Robin Soderling feel more than a little queasy today.

The Swede has been in the Federer firing line 10 times and on each occasion he has come off second best.

The most recent was in the French Open final and just three weeks on from that drubbing, Soderling is hoping to find a quick cure for his health problems if he is to have any chance of upsetting a man chasing a record 15th Grand Slam title.

"My stomach has been pretty bad since Wednesday, so I didn't eat a lot. I felt pretty bad," said the 13th seed after reaching the second week at SW19 for the first time. "And it's tough to play against Roger. I've played him 10 times, and after the matches I've never felt like I played well.

"It's not because of me, I think it's because of him. It's tough to play well against him, put it that way. I'd like to improve everything from Paris."

Revamping his game in just 22 days is almost a mission impossible. He is gifted with a thunderous forehand and has the ability to leave many opponents huffing and puffing as they chase after his winners. He also employs a high-risk strategy of blunting his opponents' strengths instead of exploiting their weaknesses. Those tactics can catch out most players but Federer is no ordinary rival. The second seed said: "What stands out to me, is that I've beaten him [Soderling] so many times that it gives me an incredible amount of confidence, knowing that if I do play my game well, I should be fine," said Federer, who has lost just once in his last 69 matches on grass.

Meanwhile, Andy Roddick is not surprised the fourth-round draw has an experienced look about it. At 26, the American sixth seed is far from the oldest competitor in the last 16, with Federer, Lleyton Hewitt and Juan Carlos Ferrero all in their late 20s, while Tommy Haas, Radek Stepanek and Ivo Karlovic have already celebrated their 30th birthdays.

With the emergence of Rafael Nadal, 23, Andy Murray and Novak Djokovic, both 22, tennis has been seen as a young man's game, but Roddick believes grass rewards maturity.

He said: "I think grass definitely takes some getting used to, unless you're [Boris] Becker or someone like that. Even [seven-time champion] Pete [Sampras], his first couple years admitted he was a little uncomfortable on it."

Roddick takes on 23-year-old Tomas Berdych on Court One today. The American will be favourite but he will be wary of the unpredictable 20th seed, who has beaten him twice in their four previous meetings.