Rafael Nadal will accept second billing at Wimbledon

New world No1 Rafael Nadal will not take offence if Wimbleon make defending champion Roger Federer top seed this year.

Nadal replaced his rival at the top of the rankings on Monday but the All England Club's grading system takes previous grass-court displays into account, which strongly favours six-time Wimbledon winner Federer.

The Spaniard said: "If I am No3 seed that is going to be a surprise for me! If I am No1 or No2, though, it won't affect anything."

He was speaking after his first competitive match on grass for two years ended with a 6-2, 6-2 win over world No112 Marcos Daniel of Brazil at the AEGON Championships.

A knee injury forced him to miss last season's grass-court tournaments but Nadal's fifth French Open title last week proved he is back on form and the clay-court master believes he is a major threat on any surface.

The 2008 Wimbledon champion said: "A year ago I was injured and now I am not — that's the big difference. I am better player now because I am running less than before and after having good results on grass I start to believe I can play well on this surface. I am now a more complete player.

"I am happy to be playing on grass and for me it is always a challenge to be here and to practise the serve, volley, slice, return and stand more inside the court than on clay. I enjoy this transition."

Nadal faces world No72 Denis Istomin of Uzbekistan in the third round at Queen's today before Andy Murray takes on Mardy Fish with the Briton having again vented his anger over drug testing.

Murray and his brother, Jamie, lost to Fish and Mark Knowles 6-3, 6-3 in the doubles yesterday but it was not the defeat which riled the world No4.

The 23-year-old appears to have been tested after the match and responded on his Twitter site with the words: "Drug testing regulations r beyond a joke (haha) amazing stuff."

There were no more details this morning to explain why Murray was so angered but last year he criticised the launch of a tougher drug testing regime.

Players must now tell their national anti‑doping organisation where they will be for one hour every day and tests can be done both in and out of competition.

An exasperated Murray said at the time: "I don't understand why we have to do it during tournament weeks when we're being tested anyway. So many things could be done better. When I wake up in the morning, the last thing I'm thinking about is drugs testing."

A win today would help Murray's mood and he beat Fish in this tournament a year ago. The American world No90 said: "Andy pretty much kicked my butt from the start here last year. If he serves well, he's extremely tough because his return is one of the best in the world."