Mardy Fish admits that going up against fourth seed Novak Djokovic on Wimbledon's Centre Court later today will seem like a bad dream.

The American is enjoying a good season, winning his third career ATP Tour title at Delray Beach in March and equalling his best performance at the All England Club by reaching the third round.

But now the 28th seed faces the daunting prospect of taking on Djokovic, the 22-year-old Serb who accepts he still has a lot to prove after winning a maiden grand slam title in Australia 18 months ago.

Fish, 27, said: "He moves great, serves real well. He doesn't have any weaknesses at all. He's one of those guys where, if he comes out and plays to his highest capabilities, he'll blow you right off the court.

"He returns really well, kind of a nightmare for a guy like me who tries to rely on some easy points on the serve. But I'll throw everything I've got at him."

Djokovic was expected to kick on from his triumph in Melbourne last year but it is British No1 Andy Murray who has taken the challenge to Rafael Nadal and Roger Federer.

Now the world No4, usually never shy about seeking the spotlight, is deliberately keeping a low profile in SW19.

He said: "I have no expectations. I can't rate myself as favourite because I think Mardy's been playing well.

"He's a big server, so to play against him on any fast surface will mean a difficult match."