Nick Kyrgios credits fitness and improved mentality with Sunshine Swing surge

WATCH: Kyrgios visited the Tennis Channel Live Desk following his third-round victory over Fabio Fognini in Miami.

Consistency and Nick Kyrgios don't usually go together. The up-and-down Aussie played just eight tournaments in 2021, getting few wins, but is off to a much better start this season.

This week at the Miami Open, he's beaten No. 7 Andrey Rublev and talented veteran Fabio Fognini, and is into the fourth round of the Masters 1000 event. At Indian Wells, he scored wins against Casper Ruud and Jannik Sinner before falling to Rafael Nadal in three sets. He also won the Australian Open doubles with Thanasi Kokkinakis.

Kyrgios says he's moving better now that he can bring his physio on tour to rehab his frequently injured knee, and is also fitter than he's been in recent seasons.

"A good pre-season in, able to get the treatment necessary, and I think it was just a combination of things. That was primarily the reason why my knee is feeling the way it feels," he told press in Miami.

"But also, I think I have just been, you know, healthier, moving a lot. I actually did a lot more gym in the pre-season than I have probably ever done."

In addition to physical improvements, Kyrgios—who has spoken about motivation problems at times—also believes he now has a better mentality when it comes to competing and playing on tour.

This is nearly my ninth year on tour. I know I'm going to have some weeks where it's incredible, and I know there are going to be some weeks where it's shocking. I'm kind of riding it, and I think it's healthier. Nick Kyrgios

"I thought I trained as hard as I did, and I'm probably in some of the best shape I have been in for a while," the 26-year-old said this week. "I could put some of it down to that as well. I'm just in a better space in my family, like I could put it down to a handful of things.

"But I think I just know like I have been playing for a long time now. This is nearly my ninth year on tour. I know I'm going to have some weeks where it's incredible, and I know there are going to be some weeks where it's shocking.

"I'm kind of riding it, and I think it's healthier. I have had some great performances. I'm happy with that."

It's not just his own play he's improved, either. Kyrgios was asked by four-time Grand Slam champion Naomi Osaka for serving tips, and their session prompted a small technical change.

"My entire three months leading up to Australian Open I probably hit no more than 200 serves. It's something that comes very naturally to me. My best advice is I told her, I was, like, 'When you start overthinking on your serve, that's when things start to get complicated,'" he said.

"[It's] the one shot in tennis that you always have complete control, so just take your time. She started sliding her foot up, a better way to get momentum rather than stepping up. She played great yesterday.

"I'm a massive fan of Naomi. I think what she can do for the sport and what she's already done, she's a great champion. She's incredible. I think she's going to inspire millions of people.

"I get really pissed off when people in the crowd say things and it affects our great champions like that, because she's carrying a lot of weight on her shoulders. She's also a normal human dealing with normal problems as well as carrying the weight of the world. I want to be first to stand up and say it's not okay. But she's awesome. I want the best success for her."

Kyrgios, who is currently ranked No.102, will go back into the Top 100 following Miami.