Murray admits he must get stronger

(GETTY IMAGES)

Andy Murray has confirmed that physical difficulties played a significant part in his defeat to Stanislas Wawrinka at the US Open this month. The 23-year-old Scot, who suffered leg and elbow problems in the third-round match, says he is still unclear as to why he struggled.

"I haven't felt like that for a very long time and I'll make sure it never happens again," Murray told the BBC.

"Physically I wasn't great and that's what I was most disappointed with. I've been very strong in that area for the last few years and it let me down a little bit, so I need to make sure I work hard, get myself in great shape again and hopefully I'll give myself another chance."

Murray, who is back in training for his next appearance at the China Open in Beijing in a fortnight's time, said that he had not had any discussions with potential new coaches following his split with Miles Maclagan two months ago. "I'm still looking into it and trying to find the best person that can help me," he said.

Laura Robson, Britain's 2008 junior Wimbledon champion, is also looking for a new coach. The Dutchman Martijn Bok will finish working with the 16-year-old after the end of her current trip to Asia.

Rafael Nadal has agreed a deal to play again at the Aegon Championships at Queen's Club next June. In all four years that the world No 1 has competed at the grass-court event he has gone on to reach the Wimbledon final.

"After the French Open, it is very important for me to feel the grass under my feet as soon as possible," Nadal said. "I tried my best in every match this year [at Queen's] and was disappointed that I could not win the tournament, but I reached the quarter-finals and it definitely helped me to feel ready for Wimbledon."