Pablo Carreno Busta to replace injured Rafael Nadal at ATP Finals

World No. 10 Pablo Carreno Busta will replace the injured Rafael Nadal in the ongoing Nitto ATP Finals. The 26-year-old Spaniard will begin his campaign against Austria's Dominic Thiem in a Group Stage match on Wednesday.

Carreno Busta was on standby in case any of the players retired hurt midway through the year-ending ATP event. Entering the tournament, Nadal's status was up in the air, especially after a knee injury forced him to pull out of his Paris Masters quarterfinal match against Serbia's Filip Krajinovic. However, Nadal declared his intention to play after collecting the World No. 1 trophy on Sunday evening.

Nadal, playing through a knee injury, put up a valiant fight before succumbing to a 7-6 (5), 6-7 (4) defeat to World No. 8 David Goffin on Monday night (Tuesday in Australia). After the loss, Nadal announced that his memorable 2017 season had come to a grinding halt.

"It was not a decision at all (to pull out of the event). It's about the pain. I cannot hold with enough power to keep playing. I tried, but (it) seriously was miracle to be very close in the score during the match," Nadal said after an emotionally-draining defeat to Goffin.

ATP Finals: Injured Rafael Nadal wanted to honour commitment

Nadal wasn't obligated to play the event since he had already secured the World No. 1 ranking. But the 16-time Grand Slam champion wanted to honour his commitment to the tournament organisers and the fans at the 02 Arena in London.

"I had the commitment with the event, with the city, with myself. I tried hard. I did the things that I had to do to try to be ready to play. But I am really not ready to play. I really fought a lot during the match, but knowing that (there) probably was a big chance to be the last match of the season."

Pablo Carreno Busta, 26, has won three titles over the course of his young career. He was pencilled in as the first alternative after World No. 7 Stan Wawrinka ended his season with an injury. Carreno Busta made headlines at this year's US Open when he reached the first Grand Slam semi-final of his career.