Broady, who is seeded 25th in qualifying for the US Open and beat American Murphy Cassone on August 23rd, said last-minute withdrawals caused players ranked close to the cut-off mark for Grand Slam main draws to needlessly go through qualifying.

The US Open main draw will be announced later on Thursday, and subsequent withdrawals will require the draw to be reshuffled, with the vacated spots going to "lucky losers".

"There should be a rule against late withdrawals from slams when you know you aren't going to play," Broady wrote in a post on Twitter on Wednesday.

"Really tough on number 1 seeds in slam qualifying seeing players they know aren't playing on the main draw list but still having to going through qualifying."

Djokovic, who has refused to take the COVID-19 vaccine, appears set to miss out on the tournament due to current US rules that require travellers to show proof of full vaccination to board flights to and enter the United States.

Djokovic was also unable to defend his Australian Open crown this year after being deported from the country over his vaccination status in January. He so far remains on the entry list for the US Open, which runs August 29th-September 11th.

Broady later explained his tweet was not about Djokovic, saying he had no issues with the Serbian hanging on to his spot out of a belief he would be able to play in the tournament.

"This tweet isn't about ND," Broady said in a reply to a Djokovic fan. "It's about players who KNOW way before the withdrawal deadline and still don't do it due to lack of caring.

"It can cost the guy one out of main draw a lot of money as qualifying isn't guaranteed...

"I think ND still believes there's a chance he plays. Totally fine."