MELBOURNE, Australia -- Until further notice, until he can approach tennis with the professionalism and cold-eyed frankness that all champions have learned to have, Nick Kyrgios will remain a tantalizing talent locked in a straitjacket of his own making. All the reasons were again on display Wednesday night at the Australian Open, his home Grand Slam, after he blew a two-set lead and lost in five to Andreas Seppi of Italy.

With the crowd shrieking for Kyrgios to rise up and pull out this back-and-forth match at Hisense Arena, the third-largest venue on the grounds, nothing symbolized the maddening behavior Kyrgios often brings to the court like the totally unnecessary between-the-legs shot he risked -- but made -- in the middle of a rally as Seppi was attempting to serve out the match at 6-5 in the fifth.

"A tweener -- didn't expect that," Seppi said in his on-court interview after finally prevailing eight games later for a 1-6, 6-7 (1), 6-4, 6-2, 10-8 win that left the crowd booing Kyrgios as he left the court.

Nobody anticipated that shot. It was a shot Kyrgios never should've tried. He was in the middle of the court. He could've simply moved his feet and set up to strike the ball with his powerful forehand, a shot that's feared throughout tennis. But instead, Kyrgios resorted to an exhibition-match shot that other pros trot out only when they have no other choice. And although it didn't lose the match for Kyrgios, his choice to hit that shot in a game he had to win showed why Roger Federer correctly had doubts that the 14th-seeded Kyrgios was ready to really contend for the title this year in Melbourne.

Nick Kyrgios failed to hold on to a two-set lead against Andreas Seppi on Wednesday. EPA/JOE CASTRO AUSTRALIA AND NEW ZEALAND OUT

"To win [it all], he drops, in my humble opinion," Federer told the Fairfax Media this week. "He's never been to a semis before. ... For me to start talking about him winning the tournament; Lleyton [Hewitt] never did it, and he was two times world No. 1 at the end of the year. I know [Kyrgios] has a big game. But he has to beat four, five amazing players. Can he do that right now? I'm not sure."

Kyrgios' talent isn't the problem. Questions about his professionalism and maturity and mental toughness still dog him. He admits it himself. Kyrgios, 21, spent large slabs of this match shaking his head in disgust at himself, barking at the chair umpire and his supporters in his box. He missed a match point of his own and his form dipped noticeably in the third set. He admitted after the match that he didn't take his offseason conditioning seriously enough and "played too much basketball." Then he shrugged and added, "Live and learn."

Kyrgios also volunteered that he knows it's a mistake that he hasn't hired a coach by now: "I think I'm the only one in the top 100 that doesn't have a coach," he said. Then he added that he hadn't bothered because, "I guess I just like the freedom of to do whatever. I like being comfortable."

But talent only gets you so far -- even the kind of eye-catching talent Kyrgios has. He runs like the wind and has a telescopic reach. He snaps off groundstrokes that sizzle. But as the match against Seppi wore on, Kyrgios didn't bother to move his feet, and he took so many nonchalant-looking cuts at shots, he was told afterward that Eurosport analyst John McEnroe accused him -- not for the first time -- of not trying. And the charge was relayed to Kyrgios in his news conference afterward.

"Good on him, good on him" is all a stone-faced Kyrgios said.

Asked later if the niggling knee injury he was fighting before this tournament caused him any sharp pain, Kyrgios shot back, "Ask Johnny Mac."

Clearly, that three-week suspension and tour-ordered therapy with a sports psychologist that Kyrgios accepted as punishment after blatantly tanking a fall match in China and getting into a verbal altercation with a fan didn't leave him chastened.

People such as top-ranked Andy Murray have tried to make allowances for Kyrgios' age and inexperience. Murray, even more than Kyrgios, knows what it's like to carry an entire country's hopes on your shoulders year after year. An Aussie man hasn't won the Australian Open since 212th-ranked Mark Edmondson did 40 years ago. But the wait for a British man to win Wimbledon was almost twice as long before Murray finally did it.

It was no surprise when Murray spoke kindly about Kyrgios last year, stressing maturity on the tour takes time. Earlier this week, Federer hit on the same theme, saying in the same Fairfax Media interview that he understands why he and other players are constantly asked about Kyrgios, but "I find it's too much sometimes."

Still, Kyrgios has had enough offers of help and opportunities to change. He agrees he simply hasn't taken them. He continues to say he doesn't really love tennis -- a point he seemed to underscore when just days after the ATP disciplined him for tanking, he decided to walk out on a contract with an tour event in the Netherlands to accept an invitation to play in the NBA All-Star weekend celebrity game this February.

It's Kyrgios' life. His choice. He skipped the Rio Olympics last August, too, after a row with Australian officials. But the consequences of his choices are also clear: Nick Kyrgios in an exceptional talent who, for now anyway, seems bent on squandering it.

"I didn't have the best preparation for this tournament," he said. "And that's on me."