Its Time for some Wimbo

Four-time champion Roger Federer could afford to relax and watch the pretenders to his Wimbledon throne play catch-up on Monday as All England Club chiefs hoped for an end to the torrential rain which played havoc with the first week.

Top seed Federer was handed a free pass to the quarter-finals when fourth round opponent Tommy Haas pulled out with a stomach injury.

In stark contrast, second seed Rafael Nadal has yet to play his third round match after his scheduled clash with Sweden's Robin Soderling was one of the matches which was washed away in Saturday's deluge.

Federer won't play again until Wednesday while the Spaniard, the runner-up to the world number one last year, faces the prospect of three matches in three days.

Women's top seed Justine Henin, who has yet to win a Wimbledon title, opens Centre Court action with a fourth round clash against experienced Swiss Patty Schnyder.

Play on the two main show courts was brought forward by two hours on Monday in an effort to clear the backlog after Saturday's rain -- but the weather frustrated organisers once more with showers forcing players to kick their heels in the locker rooms for over an hour.

Only two matches were completed in the 75 minutes of action seen on Saturday -- and the washout cost tournament organisers an estimated one million pounds (two million dollars) in ticket refunds.

Also in action on Monday are former women's champions Venus and Serena Williams while, in the men's event, 2002 winner Lleyton Hewitt takes on Guillermo Canas in his delayed third round match.

Meanwhile, security was stepped up around Wimbledon in the wake of the attempted car bomb attacks in Glasgow and London.

A police helicopter hovered above the venue in south-west London while all entrances were protected by a series of vehicle-blocking concrete slabs to foil similar attacks.

Ian Ritchie, the All England Club's Chief Executive, said the measures had been introduced on police advice that the tournament could be a target.

Ritchie said: "The barriers and extra searching of bags will make it slower for spectators getting in to the ground but the safety of everyone attending the Championships is of paramount importance and I'm sure everyone will understand why these precautions are necessary."