American Reilly Opelka is the latest tennis star to cop a serve for venting his pre-Australian Open frustrations, claiming “nobody feels welcome” in Melbourne.

Opelka wasn’t even among the 72 players forced into two weeks of hard quarantine after virus infections emerged among Open arrivals.

He has been allowed to train for up to five hours for the Open and the week-long Melbourne Summer Series preceding the season’s first grand slam since his arrival in Victoria.

But that didn’t stop the world No.40 from taking to social media for a moan.

“Nobody here feels welcome. But it’s too late, I have flown across the world. Would be pointless for me to go home now three days before the AO,” Opelka said when reminded he was under no obligation to compete.

“Well I’m not going to go home after all this. I didn’t realise how it didn’t make sense for us to be in Australia in the first place, till after I got here. Never fun being somewhere you aren’t welcome.”

Tweet from @ReillyOpelka

Despite copping some public backlash, Opelka did receive support from Nick Kyrgios’s coach Matt Reid.

“I’m happy you came, Reilly,” Reid posted with an emoji of a face throwing a kiss.

Hundreds of Australian Open players and support crews were confined to their hotel rooms in Melbourne again on Thursday after this week’s revelations of a positive COVID test in a quarantine worker.

Play at warm-up matches for the Open was abandoned on Thursday, but resumed on Friday.

Later on Friday, Tennis Australia announced via Twitter that all of the players caught up in this week’s isolation had returned negative virus tests.

Tweet from @jillastark

Tweet from @GraemeMonteith

Tweet from @westernaustral7

Pushing ahead with the grand slam has become a contentious issue in Melbourne. Despite the controversy, however, Tennis Australia chief executive Craig Tiley said on Thursday he was confident the tournament would begin as scheduled.

“We are starting on Monday,” he said.

“There’s no intention of changing the time for the Australian Open.”

Opelka’s whining comes a week after Mr Tiley reminded players they had the opportunity to compete for a record $80 million in prize money at the rescheduled slam.

First-round losers are guaranteed $100,000 after Tennis Australia paid the bill to fly in players from all over the world for the Melbourne major.

Opelka’s mood wouldn’t have lightened at all by a shock 7-6 (8-6) 7-6 (7-4) loss to the Netherlands’ world No.159 Botic van De Zandschulp in his warm-up event on Friday.

-AAP