Eight of the world's best men's players will close a fragmented 2020 season when they battle to be crowned the ATP Finals champion in the event's final year in London.

Nadal, 34, faces in-form Russian Andrey Rublev, who is making his Finals debut.

"Of course I want to win this tournament, but it is not frustrating that I haven't yet. I'm super happy with my career," Nadal told BBC's World Service.

"But I will keep fighting for this trophy and this is another chance."

Nadal and Rublev have been drawn in an exciting group alongside Austria's US Open winner Dominic Thiem and Greece's defending champion Stefanos Tsitsipas, who start the tournament on Sunday in a rematch of last year's final.

World number one Novak Djokovic starts his bid for a record-equalling sixth title - and a first since 2015 - against Argentine debutant Diego Schwartzman in Monday's day session.

The Serb, who is already guaranteed to finish 2020 at the top of the rankings, will also face Russia's Daniil Medvedev and Germany's Alexander Zverev.

"Coming into the tournament and knowing I have clinched the year-end number one releases some of the pressure, but it doesn't change why I am here - I want this trophy as much as anybody," said the 33-year-old.

"The success I've had previously in London helps me feel more comfortable and confident with my game."

How the contenders have reached London

The eight singles players are split into two groups, named Tokyo 1970 and London 2020 in tribute to the event's 50th anniversary.

Top seed Djokovic and second seed Nadal were separated, with the rest of the players drawn out alongside them on Thursday.

Group Tokyo 1970

Djokovic: Serbia's world number one is the favourite to win a sixth title and level Roger Federer's record. That would nicely round off another impressive season for the 33-year-old, who has only lost three of his 42 matches and equalled Pete Sampras's record of finishing as the year-end number one for a sixth time.

Medvedev: Failed to win a match on his Finals debut last year as the physical and mental exertions of his breakthrough season took their toll. After a truncated 2020, the 24-year-old Russian looks better equipped to perform at his best having won the Paris Masters last week.

Zverev: Long touted as the next major star in the men's game, the 2018 champion was close to claiming a first Grand Slam title at the US Open, only to fall in the final to his friend Thiem. Also reached the Paris Masters final last week despite the backdrop of domestic assault allegations from his ex-girlfriend, claims which the German denies.

Schwartzman: Another debutant at the end-of-season Finals after clinching the remaining spot last week. The diminutive Argentine reached his first Grand Slam semi-final at Roland Garros and earned a top-10 ranking for the first time as a result.

Group London 2020

Nadal: Winning the ATP Finals would fill the biggest gap left in the Spanish left-hander's vast collection of prestigious trophies. Last month he won a record-equalling 20th Grand Slam singles title at the French Open and the second seed is hoping to add a rare indoor title.

Thiem: The powerful Austrian ended the Big Three's stranglehold on the Grand Slams when he won the US Open in September. That should give added belief to the world number three as he looks to go one step further in London than last year's defeat by Tsitsipas in the final.

Tsitsipas: Twelve months ago, the 22-year-old Greek won the biggest title of his career on his ATP Finals debut. While he has not been able to add a Grand Slam victory in a disrupted 2020, he has consolidated his place among the world's best, but comes into the event having struggled with a leg injury at the recent Paris Masters.

Rublev: One player who will also remember 2020 for the right reasons, having enjoyed an impressive breakthrough year. The hard-hitting Russian has won more ATP matches (40) and claimed more tour titles (five) than any other player, enabling him to reach the world's top 10 and qualify for his first ATP Finals.

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Salisbury carries British flag in London

Doubles player Joe Salisbury is the only British representative at the tournament, having qualified alongside American playing partner Rajeev Ram for the second successive year.

The pair are the current Australian Open champions, and also reached the US Open semi-finals and French Open quarter-finals this year.

However, Jamie Murray and Neal Skupski missed out on the remaining spot in the doubles - despite reaching the Sofia Open final this week.

'Not fair to finish in London without crowds'

After a successful 12-year stint at the O2 Arena in London, the event will move to Italian city Turin from 2021.

The farewell will not go as planned, however, with fans unable to attend because of the coronavirus restrictions.

More than 250,000 fans watched the matches over the course of last year's event, and almost three million have visited the 18,000-capacity arena since 2009.

Other key changes because of the pandemic are line judges being replaced by an electronic calling system and the players staying together in a hotel next to the O2 Arena.

Usually the players travel to North Greenwich from central London by boat on the River Thames, but the coronavirus restrictions mean they are not even allowed to walk the short distance from their hotel to the arena.

"The experience to play here in London has been one of the best," said Nadal, who has twice lost in the final.

"The atmosphere and organisation has been great; the event has been very popular around the world. It is not fair to finish it without crowds.

On the move to Turin, he added: "Tennis needs to keep moving around the world and keep promoting our sport."

When will the matches be played?

The tournament schedule remains the same as in recent years, with the group matches being played from Sunday to Friday across two daily sessions.

The afternoon session starts at 12:00 GMT every day with a doubles match followed by a singles match at 14:00.

Doubles also kick off the evening session at 18:00 GMT, with a singles match rounding off the day at 20:00.

Following the group stage, the tournament culminates in a finals weekend. The semi-finals take place on Saturday before the champions are decided on Sunday.

How can you stay across all the action?

You can follow the ATP Finals across BBC TV, radio and online.

Watch live coverage on BBC Two and the BBC iPlayer, with radio commentary available on BBC Radio 5 Live Sports Extra.

There will also be live text commentary and reports on the BBC Sport website and mobile app.

Find out the full details here.