Rafael Nadal expects to be fit enough to play in the season-ending ATP World Tour Finals in London, despite currently nursing a long-standing knee problem.

The Spaniard has been dogged by knee issues throughout his career and last week was forced to withdraw from the Paris Masters with a similar problem, having pulled out of the Swiss Indoors the previous week.

Nadal secured the year-end world number one spot and beat Pablo Cuevas to reach the quarter-finals in the French capital before opting to pull out as he sought treatment ahead of the concluding tournament of 2017.

"Hopefully the knee is good," Nadal told Sky Sports. "I've done everything I've needed to do in order to get ready for London. Now it's the moment to wait and practice at the O2 over the next couple of days. Let's see if I am able to be 100% to compete.

"If nothing happens, then I will play. I visited my doctors after the Paris Masters – it was a tough day for me having to pull out of Paris. Pulling out of any tournament in the world is tough, but pulling out of the city of Paris is especially tough for me.

"That's how it is. I went back home and visited the doctors to do some treatment. I expect the treatment to work and be ready for here. I know I'm confident because I'm having a great season with one event to go. I am here to try my best."

Despite Nadal's optimism, his backroom team has issued contradictory statements regarding the 31-year-old's fitness. Doctor Angel Ruiz Cotorro has urged the left-hander to not risk further damage to his troublesome knees by playing at the O2 Arena, though coach Carlos Moya sees no problem with Nadal competing next week

Though Nadal is the top seed – six titles this year including two grand slams ensure he will end the year as the oldest year-end number one in history – Roger Federer is the tournament favourite, having beaten his great rival in all four meetings this year.

Nadal will open his campaign against David Goffin on Monday (12 November) and will also face Dominic Thiem and Grigor Dimitrov in the round robin stage. Nadal has never won the ATP Finals, twice finishing as runner-up in 2010 and 2013 when he lost to Federer and Novak Djokovic respectively.

Should Nadal pull out either before or during the round-robin stage then Pablo Carren Busta or Juan Martin del Potro could stand in as alternates, having finished 10th and 11th respectively in the race to London.

The tournament has already been dogged by a series of injury withdrawals during the tennis season. Reigning champion Andy Murray, five-time winner Novak Djokovic, Switzerland's Stanislas Wawrinka and Japan's Kei Nishikori are all absent having called time on their campaigns early due to varying fitness concerns. They are not expected to return to the tour until 2018.

Rafael Nadal
Nadal has never won the ATP Finals but heads to London as the year-end number one. Getty Images