Tomic was defeated 6-2 6-4 7-6 (7-3) by world No.7 Marin Cilic on Monday night on his return to the tournament, a year after losing in qualifying for his home grand slam.
He then closed the door on a Davis Cup return under Hewitt and exposed deep rifts among Australian players.
“No-one likes him any more,” Tomic said of Hewitt.
“We have a lot of issues that not a lot of players are happy about. We all know who those players are. Myself, (Thanasi) Kokkinakis, (Nick) Kyrgios.”
Kokkinakis, who defeated Roger Federer in an injury-ravaged 2018, was overlooked for a wildcard at the 2019 tournament in favour of Alexei Popyrin, Marc Polmans and Alex Bolt.
Tomic alleged that Hewitt’s promotion of Open debutant Polmans, the world No.169, and Bolt, who has at played three majors without winning a match, was improper.
“He used to hate Tennis Australia, it’s weird. Now he loves them. What’s happened here?” he said.
“All these guys that got wildcards are under a system … Polmans, Bolty, Jordan Thompson.
“They’re all under his Lleyton’s wing under the management company. It’s all conflict of interest.
“And then he’s in Davis Cup and he’s doing the wrong thing and everyone’s leaving.
“Lleyton’s legacy and his tennis speaks for itself. He’s an unbelievable champion. But what he’s doing now is wrong.
“I hope he gets moved and we can go back to having a good captain.”
Hewitt and Tennis Australia have been approached for comment on the allegations.
Hewitt’s manager David Drysdale expected Hewitt to respond later on Tuesday.
“I’m not going to comment on it … there is a number of inaccuracies and I’m sure Lleyton will address all of that this afternoon,” Drysdale told SEN.
Ex-coach Roger Rasheed defended Hewitt’s management of the national team, saying he had the right to steer it as he wished.
“It’s like a coach of a football team,” Rasheed told Big Sports Breakfast.
“There are always going to be players that actually love the coach. There is going to be a few players, if they’re not getting a game and they think they should be getting a game, they’ll actually have different feelings for the coach.”
He said the “pot shots” were not warranted as Hewitt had given so much to the sport, advising Tomic to “put his head down” and focus on his fitness to play day in day out on the tour.
Tomic’s incendiary remarks were in contrast to his performance against Cilic, where he pushed last year’s finalist and came back from 5-2 down in the third set to force a tiebreak.
Kokkinakis and Kyrgios are scheduled to play their opening-round matches at Melbourne Park today.
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