World No. 1 Rafael Nadal said Friday he has "high hopes" that he will be fit to play in the ATP Finals, which begin in London on Sunday.
Nadal, 33, suffered an abdominal strain at last week's Paris Masters and withdrew before his semifinal.
The injury left Nadal, who is battling with Novak Djokovic to end the year ranked No 1, unable to serve for a few days, but he said he is improving.
"I need to go day-by-day," Nadal told reporters at London's O2 on Friday. "I'm happy to be here, because after last Saturday in Paris, I didn't know if I would have the chance to be here. So I'm excited to be here after a couple of years without being able to play.
"I need to see how things evolve every single day. I have good hopes to be 100% ready for Monday."
Nadal, scheduled to play the defending champion Alexander Zverev in his first match Monday night, has qualified for the season-ending ATP Finals 15 times, but injuries have limited his play in the event to eight times. He has completed it only seven times.
He missed the tournament in 2018 and pulled out after one match in 2017. Barring any setbacks, though, Nadal believes he is playing well enough to have a chance to win the title for the first time in his career.
"I am confident that I can be very competitive, but of course it's a tournament that you will face the top guys since the beginning, so you need to be 100% ready," he said.
"But I really hope I will be able to serve every single day a little better, and my hope is to be on Sunday serving normal."