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.
Spain's Rafael Nadal, searching for his first title at the end-of-season event, plays in the evening session when the tournament starts on Sunday.
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.