Upbeat Andy

Andy Murray admits he's playing his best-ever tennis, as he looks to capitalise on the growing frailties of his rivals and capture a second US Open title.

Ahead of today's start to the season's final Grand Slam, the 29-year-old is the Man of the Moment.

Since losing the French Open final to Novak Djokovic in June, Murray has won Queen's Club, a second Wimbledon title and successfully defended his Olympic crown in Rio.

His career-best 22-match win streak came to a halt at the hands of Marin Cilic in the Cincinnati final last weekend when he simply ran out of gas.

But that hasn't dented his confidence that he can claim a second US Open, four years after his breakthrough in New York saw him become the first British man in 76 years to win a Grand Slam title.

At 29, three-time Major winner Murray admits he is taking positives from being in the twilight of his career.

"You have to make the most of every opportunity. It's a slightly different mentality to maybe when you're younger and you feel like you have a bit more time on your side," said Murray.

Murray has played in all of the first three finals of the Majors in 2016, losing to world No. 1 Djokovic in Melbourne and Paris before defeating Milos Raonic in straight sets in the Wimbledon final.

Murray's consistency on the tour in recent weeks is in stark contrast to the roller-coaster fortunes of reigning champion Djokovic.

After he won a maiden French Open to complete the career Grand Slam, all talk was of the Serb going on to retain his Wimbledon and US Open titles and clinch a calendar Grand Slam.

The expectations proved too heavy a burden when the 12-time Major winner was dumped out of Wimbledon in the third round for his earliest loss at a Major in seven years.

A shock first-round defeat at the Olympics by Juan Martin del Potro and a withdrawal from Cincinnati with a wrist injury suggested all is not well with the 2011 and 2015 US Open winner.

"I am not 100 per cent. Hopefully on Monday, when it all starts, I will be there," said Djokovic, who faces big-serving Jerzy Janowicz in his opener.

Outside of the top two, five-time champion Roger Federer, who has played every US Open since 2000, called time on his season after aggravating a knee injury in a five-set semi-final defeat by Raonic at Wimbledon.

FATIGUE

Fellow old-stager Rafael Nadal, the 2010 and 2013 US Open champion, won gold in doubles at the Rio Olympics but lost the singles bronze medal play-off to Kei Nishikori.

The Games were his first outing since an injury-enforced early withdrawal from the French Open, and the punishing schedule of 13 matches in 12 days in Brazil and then Cincinnati caught up with him when he lost in the third round in the American city.

Other contenders are likely to be world No. 3 Stan Wawrinka, a two-time semi-finalist, sixth-ranked Raonic, who has yet to get past the last 16, and world No. 7 Kei Nishikori, the 2014 runner-up. - AFP.