The Professional Tennis Players' Association (PTPA) was set up by Djokovic and Canadian Vasek Pospisil in 2020.

Andy Murray, coming off his first title of 2017 at Dubai, was again brought up short in Indian Wells, where his best showing is a 2009 runner-up finish to Rafael Nadal.

Ivo Karlovic was the only seeded player in action on day one of the Auckland Classic but he failed to fire on centre court, losing to Vasek Pospisil, who is ranked 16 places below the world number 23.

Juan Martin del Potro lost 4-6, 6-7 as he showed the rust after months of left wrist injury rehab. Del Potro, who had come back from right wrist surgery in 2010, underwent surgery on his left wrist last March.

Vasek Pospisil, ranked 62nd in the world, fired 14 aces in his 7-5, 6-3, 6-4 victory over Go Soeda, who was drafted for singles duty in place of Tatsuma Ito, who fell to Milos Raonic in straight sets.

Eugenie Bouchard will partner Vasek Pospisil in the Canadian team at the event from January 4-10.

Roger Federer defeated Vasek Pospisil 7-6 (7/4), 5-7, 6-2 in just over two hours in Cincinnati Masters.

The five-time champion will bid for a sixth trophy on Sunday when he faces holder and top seed Juan Martin del Potro, who overcame a nose bleed and a stubborn Edouard Roger-Vasselin, 6-4, 4-6, 6-2.

Djokovic said he hopes to recover from the change of the time zones and jet leg after losing the U.S. Open final to Rafael Nadal on Monday.

Raonic beat 71st-ranked Vasek Pospisil 6-4, 1-6, 7-6 (7/4) and will make his biggest ATP rankings move on Monday when he will become the first Canadian in the top 10.