Shanghai - With Rafael Nadal in injury crisis and missing the Masters Cup, healthy contenders began finding their form in smoggy Shanghai under the closed roof at the Qi Zhong stadium for the season-ending classic starting on Sunday.

Andy Murray, playing the eight-man wrap-up event for the first time in his career, has been keeping a relatively high profile, attending the midweek draw ceremony and earning praise from former great John McEnroe.

"When Andy Murray first came on the scene three or four years ago you heard people say that he could win 'majors,' and he's putting all that together now," said McEnroe, speaking to officials of the senior Black Rock Masters in London next month.

"What I love the most is how incredibly well he's moving. It's unbelievable.

"Most people can't move on the court like that and find the position and the angles that Andy's able to come up with. The way he's able to keep an opponent on his heels is really hard to do.

"He believes in the way he plays and he doesn't change his game plan - he mixes up his shots so well. He's got the hands and he can play up at the net as well and he's got a great brain and head for tennis."

Murray's rising game is in sharp contrast to that of Nadal, first number one player to miss the Masters Cup since it went to the current format in 2000.

The four-time French Open champion who won his first Wimbledon and Olympic gold medal in this season of eight trophys, pulled out of Shanghai on Monday with the right knee tendinitis which forced him to quit last Friday at the Paris Masters.

Now, the subdued Spaniard is worried that he might not pull up fit for the Davis Cup final in Argentina November 21-23. "If I'm only 40 per cent, I won't go," he told Spanish radio. "I have to see how the knee pulls up."

Nadal is desperate not to miss the Davis date at Mar del Plata. "Who doesn't want to play the Davis Cup final? It's my last major objective this season.

"Any player would want to be there, and I'm not an exception."

Nadal is current resting until the weekend at his island village of Manacor on Mallorca, with more tests on his troublesome knee set for early next week as the Masters Cup goes deep into the group stage. (dpa)