Novak Djokovic withdrew from his men's doubles match at the Western & Southern Open on Sunday due to neck pain.
The world number one remains in the singles draw, however.
Djokovic was scheduled to team up with Filip Krajinovic for a match against Tommy Paul and Frances Tiafoe at Flushing Meadows but the Serbian duo have been replaced by compatriots Dusan Lajovic and Nikola Cacic.
The 17-time grand slam champion is due to face Ricardas Berankis in the second round of the Western & Southern Open on Monday.
Djokovic is the leading contender for glory at the US Open, which is due to take place behind closed doors from August 31.
Rafael Nadal has opted out of the major due to concerns over coronavirus, while Roger Federer will be absent after undergoing knee surgery.