Andy Murray has been warned by one of his closest rivals that he must withdraw from Wimbledon if there is any risk of aggravating his wrist injury.

Murray's participation at Wimbledon, which begins on Monday, is still under serious doubt as he continues his rehabilitation from the tendon damage suffered to his right hand at the Hamburg Masters on May 15.

The British number one and tournament eighth seed will take his place in Friday's draw and plans to leave it until as late as possible before making a final decision on whether to compete.

American James Blake, the ninth seed, believes Murray will play at SW19 even if he has not made a full recovery but insists such a bold move would be fraught with danger.

Blake claims the 20-year-old Scot may not only be jeopardising his long-term fitness, but doubts how far he would progress at the All England Club while carrying his injury.

"I don't know all the details but I've heard that if he's at 90% then he's still going to play," said the world number nine.

"If you're 90% then you shouldn't play because the difference between being top 10 like Andy is and top 80 or top 100 is maybe 5%.

"So if you're playing at 90% you won't win very many matches. I know from experience that it's dangerous to play with a small injury.

"I've done it and know what it's like. You're so competitive and the adrenaline starts so that no matter how careful you want to be, you're not.

"You're never careful because you want to win so badly. The adrenaline is pumping so much that you don't know when to stop and you can possibly end up making the injury worse.

"In the match you don't feel the pain but afterwards you do. It could then become a chronic thing that keeps you out for longer.

"If he's still injured and the doctors don't think he should play, I'd listen to that advice.

"But if he's totally better then he should take his place in the draw because he's earnt his right to be there."

America have not produced a Grand Slam winner since Andy Roddick stormed the US open in 2003, leading to concerns the national game across the Atlantic is in crisis.

But Blake is confident both himself and Roddick have a batter chance of triumphing at Wimbledon than Murray, whose injury has forced him to miss the French Open and Artois Championships.

"Right not I don't think Andy Murray is any closer to winning Wimbledon than an American player," he said.

"His wrist injury means he hasn't had any match preparation so it's going to be really difficult for him this year.

"But in my opinion Andy Roddick is the second best grass player in the world.

"I would make Andy second favourite after Roger Federer. I'd like to think my chances are better than Andy's too."

Blake was speaking at today's launch of 'Turbo Tennis', an initiative that reduces competitions to a single afternoon and matches to just 30 minutes.

Murray will be among the competitors for the UK leg of Turbo Tennis - which is to be staged at the O2 Arena on September 15 - alongside Blake Tim Henman, Jamie Murray, Goran Ivanisevic and Pat Cash.

"I don't think tennis needs a change to overhaul the game but something like this can show different ideas and perspectives and maybe attract younger fans," said Blake.

"This excites younger fans who may become fans of certain players and then go and watch Grand Slams. It's an exciting aside to the normal tour."