Daniil Medvedev, who won the US Open in 2021, is the defending ATP Finals champion having won the title in 2020.
Djokovic has not played since losing in straight sets to Russian Daniil Medvedev at Flushing Meadows in September.
The 23rd seed battled back from 4-6, 1-4 down to move past the Russian 4-6, 6-4, 6-3 and reach the quarter-finals in Indian Wells for the first time.
Daniil Medvedev didn't face a break point and converted three of his seven break chances, completing the match in 72 minutes.
The ATP Finals 2021 will close out the men's tennis season at the end of the year and so far, only three of the eight spots in the tournament have been filled.
Novak Djokovic's quest for a Calendar Grand Slam ended as he was beaten by Daniil Medvedev in straight sets in the US Open 2021 final.
Novak Djokovic will contest his 31st major final on Sunday, which ties Roger Federer for the all-time record, and his 9th at the US Open, which breaks a tie with Pete Sampras and I...
Felix Auger-Aliassime reached his first Grand Slam semifinal after Carlos Alcaraz retired following the fourth game of the second set in Arthur Ashe Stadium.
Novak Djokovic entered the quarterfinal of the US Open 2021 as he defeated Jenson Brooksby in four tough sets.
Day 1 also features second seed Daniil Medvedev and eighth seed Casper Ruud against French veterans Richard Gasquet and Jo-Wilfried Tsonga, respectively.