'That's just the reality': Nick Kyrgios makes 'sad' admission after first-round exit from Brisbane International

Nick Kyrgios has admitted he's unlikely to return to peak fitness having undergone several surgeries on a string of injuries in the past three years.

After the 6-3, 6-4 loss to Aleksander Kovacevic in the first round of the Brisbane International on Tuesday afternoon, Kyrgios admitted he once held the "delusion" he "genuinely thought (he) was unbeatable".

But the 30-year-old – who is pushing for a wildcard at the Australian Open – said that belief is no longer with him.

READ MORE: Demon leads Aussie fightback to book quarter finals

READ MORE: Superstar poised to switch clubs in $130m EPL stunner

READ MORE: Cricket Australia bans ABC after stinging comments

"When you're at the top of the sport, I genuinely thought I was unbeatable," he said in his post-match press conference.

"I'd go out on court and I thought, 'no one can genuinely beat me'. You actually have that confidence and the delusion that you are that person.

"I just don't think that after you have these surgeries ... they kind of pull you down and it's like you don't have that belief anymore."

Kyrgios has barely played since losing the 2022 Wimbledon final to Novak Djokovic, and has undergone a wrist reconstruction and two knee surgeries.

The Aussie tennis summer kicks off with the 2026 United Cup from Friday, January 2. Watch it live and free on Nine and 9Now.

But he cruised through his opening three service games in a clear indication that his biggest strength on the court was still there when he needed it.

However, his opponent was looking equally confident on serve in the opening set and at one stage, Kyrgios flat-out admitted he was finding it difficult.

Things started to unravel mid-way through the opening set when he started clutching at his elbow in clear discomfort, before Kovacevic broke Kyrgios' serve for the first time.

"Perhaps the lack of matches and conditioning [is an issue]," John Millman said in commentary for Nine.

Kovacevic took full advantage of the situation and won the first set with relative ease.

Kyrgios downplayed any injury concerns post-match, putting the pain down to a general lack of match fitness.

"It's sad in a way, but that's just the reality," he explained.

"(From) finals of Wimbledon, quarter finals at US Open, I barely lost a match all year (in 2022), and then you have I guess these surgeries...

"I guess the people out there, they think you just go under the knife and come back and it's just ... you sit on the couch until he recovers, and you throw him back out there and he's the same player.

"That's just not how it is. It's not reality. It's just sport."

Kyrgios will have a chance to keep upping his match fitness when he teams up with Thanasi Kokkinakis in the men's doubles round of 16 on Wednesday.

The Special K's returned in style on the weekend in a three-set thriller and playing in that format could be their best hopes of lighting up Melbourne Park later this month.

"So you can't be too upset – that's why you have to really be grateful for moments like that doubles match the other night, and the fact that I got through this and I'm ready to play doubles (on Wednesday)," he said.

"I'm still extremely happy with myself and proud of myself."

With the elbow issue clearly nagging him, Kyrgios had to reach into his bag of tricks to keep the match alive and did exactly that, catching Kovacevic off-guard with an underarm serve that allowed the former Wimbledon finalist to hold serve.

"We said we'd see one," Millman said on commentary.

With the second set locked at 4-4 and Kyrgios on serve, Kovacevic broke him again and then had the opportunity to serve for the match, where he made no mistakes and sealed the victory, which was no doubt unpopular with the bulk of fans in Brisbane.

Speaking post-match, Kovacevic - who is currently at his career-high ranking of No.58 - admitted it was tricky to navigate playing against Kyrgios right now.

"It was a tough one to approach, you don't always know what you're gonna get with Nick," he told Nine's Tom Reh.

"It's tough to scout him recently, because he hasn't been on tour for a while or playing serious matches. I didn't know what to expect, I just knew I had to be pretty locked in.

"To be honest, I was expecting a little more than that in terms of adversity."