All eyes on Djokovic as US Open gets underway today

Serbian top seed Novak Djokovic will be the centre of attention when the final Grand Slam of the 2021 calendar, US Open, showdown begins today on the hardcourts at Flushing Meadows

Djokovic will try to complete the first calendar-year men's singles Grand Slam in 52 years and become the all-time men's leader in Slam titles by capturing the US Open.

After winning this year's Australian Open, French Open and Wimbledon, a fourth victory for Djokovic at Flushing Meadows will enable him to enter an exclusive club.

Only five players have previously won all four majors in the same year, with Australian great Rod Laver the only man to have achieved the feat in the Open era.

Five past champions won't be in the field when the showdown begins Monday on the hardcourts at Flushing Meadows, with Roger Federer, Rafael Nadal, Stan Wawrinka, Juan Martin del Potro and 2020 winner Dominic Thiem absent due to injuries.

That leaves the main obstacles in Djokovic's path to a 21st career Slam crown as a set of rising 20-something talents trying to build their trophy hauls -- Russia's second-ranked Daniil Medvedev, Greece's third-ranked Stefanos Tsitsipas and fourth-ranked Olympic champion Alexander Zverev of Germany.

Australia's world number one Ashleigh Barty is widely considered as the player to beat in the women's singles, although Japan's defending champion Naomi Osaka is aiming to lift the title for the third time in four years. With an all-court game that has yielded five titles so far this year, 25-year-old Barty has cemented her place as the world number one and goes into the US Open as the favourite.

After lifting the Cincinnati title last week, Wimbledon champion Barty has notched a tour-high of match wins (40) in 2021 and a 14-1 winning record against top-20 opponents.

Meanwhile, players' mental health is also in focus after four-time Grand Slam winner Naomi Osaka led the charge for her fellow athletes this year.

The 23-year-old withdrew from the French Open after being fined and threatened with expulsion for refusing to attend media conferences, which she said had an adverse impact on her mental health, and disclosed she had suffered from depression for years.

The incident led Roland-Garros organisers to concede that the sport's governing bodies needed to do better and the United States Tennis Association (USTA) this week announced a mental health initiative for players in partnership with the Mount Sinai Health System.