Pretenders to the crown

Pete Sampras: Won the US Open three times

BBC Sport Online's Mark Jolly looks at the players who can knock Sampras and Agassi off the top of the tennis ladder.

In the past seven years, Pete Sampras has won the US Open three times, with Andre Agassi and Pat Rafter picking up two titles each.

But this time around, the ravages of long careers on the tour could mean there will be a new champion.

Those hoping to depose of the old guard include two-time French Open champion Gustavo Kuerten, Magnus Norman, who led the ATP Champions Race for much of the first half of the year and young Marat Safin who has been in great form on both clay and hard courts this year.

Rafter, champion in 1997 and 1998, has missed much of the last year with a shoulder injury which first became apparent at Flushing Meadows in 1999.

Rafter: Two titles

Doctors have told the Australian, still only 27, that after the operation on the rotator cuff in his right shoulder last October he only has a limited number of serves left in him.

Recent events have borne that out.

The Australian reached the Wimbledon final in July but the injury played up again in the Masters Series event in Toronto and looks likely to hinder his hunt for a third title.

Sampras has been even more unlucky.

Two years ago the American ran into the net during his semi final with Rafter and strained a thigh muscle. Sampras looked to be edging to victory up to that point but was slowed down enough for Rafter to win in five sets.

Two days

Last year, he did not even make the first round. He herniated a disc in his back two days before the tournament began, an injury that effectively saw him lose his six-year grip on the world number one spot.

The American, now 29, picks up a worrying number of niggling injuries. Typical of these was the tendinitis at the bottom of his shin he suffered during the successful defence of his Wimbledon crown.

But injuries to those two last year certainly opened the door for Agassi, who was in the middle of a run that saw him win three Grand Slam championships and reach the final of the fourth.

Agassi: Fitness doubts

But now Agassi, 30, has doubts over his fitness. A minor road accident after Wimbledon caused havoc to his preparations for the US Open, with his back the problem.

The pain forced him to pull out of the important Masters Series event in Cincinnati in August.

But the American got the matches he needed to be sharp for Flushing Meadows with a tremendous run at Washington.

Sampras, Rafter and Agassi have been around long enough to know how to reach their best form when it matters most - but there is no doubt they will be severely tested this year.