As the stars of the game battled it out at the United Cup in Perth, Petra Marcinko was soaking it in.

One year on from capturing the Australian Open girls' title, the 17-year-old Croatian player was using the inaugural mixed-gender competition as preparation for her pro Grand Slam qualifying debut in Melbourne this week. Although she played in only a mixed doubles match, which she lost, it was the overall experience that counted.

"All these players I was looking up to when I first started playing tennis -- Donna [Vekic], Petra [Martic], Borna [Coric] -- since I was little, I heard about them on the news," Marcinko told as she watched from the sidelines. "Now I'm on a team with them."

But Marcinko will be on her own again as she resumes what's been a meteoric rise through the WTA rankings. That suits her just as well. In 2022, with the Australian Open as a springboard, she rose from No.905 to No.194 over the course of the season.

Her 35-13 record included two Top 100 wins -- over Rebecca Peterson in Rabat, also her first tour-level victory, and against Jule Niemeier in Billie Jean King Cup action -- as well as three ITF World Tour titles.

Rabat: Junior No.1 Marcinko, 16, upsets Peterson on WTA debut

"Those were the most memorable matches," Marcinko said. "Peterson, I came into the first set 6-0, I started really good. But she's an experienced player and I knew it was not going to go easy. In the end it was a big fight, a tough match. I was dead after. Physically good, but so exhausted after grinding through the whole third set.

"Niemeier, it was one of the best matches I've ever played. I did everything right and everything was going for me. I lost against her two times before that, but they were on clay and I knew what I was going to do. And even though I'd lost, I knew I had the level to compete with her. I hadn't started well the other two matches, which gave her the advantage, so I changed that. I put more pressure on her serve. And of course it was different, being in Croatia."

Rookies learning from the best at United Cup

Marcinko, who believes her generation is keen to both see and compete in more mixed-gender events, has been using her time on the Billie Jean King Cup and United Cup teams as a learning experience.

"You get to see these professionals, the way they work and practice," she said. "You see the way they are on court -- how calm they are. The kind of things I still have problems with, my ups and downs -- you don't see it. Even if they maybe feel nervous -- you don't see it."

Petra Marcinko, third from left, cheers on Petra Martic during 2023 United Cup action.

Trevor Collens/Tennis Australia

As much as she enjoys team spirit, though, there's no doubt that tennis' fundamental appeal for Marcinko is its individual nature.

"I like being alone," she said. "I like solo sports. I like how there are so many combinations of things you can do. I like how it's so mental, it's not all the same every time. Every match is different for so many reasons, which makes it fun to play.

Marcinko had not set any goals for herself beyond experiencing the pro tour before her 2022 season and is approaching 2023 in the same spirit.

"If I do that, I just put pressure on myself," Marcinko said. "The biggest thing for me now is to improve physically, because I started doing gym and fitness pretty late. The game is here, you know, but I need to get on the level where I can match the girls on the WTA physically."

There's no doubt of her ambition. The game that Marcinko refers to is one that she wants to be characterized by all-round excellence.

"I'm an aggressive player," she said. "I like to go in, I like to finish the point first. But when I was little, I didn't have much power advantage over the opponent, so I had to use my brain. I can think too. I'd like to improve my footwork so I can be a good defensive player as well, though. I want all the aspects."

Marcinko has been telling everyone ever since winning here that Melbourne is her favourite location on tour, and she'll take that positivity into her first qualifying match against former World No.21 Mona Barthel on Monday. But there's a bigger matchup that she particularly wants to happen in 2023.

"I want to play Iga Swiatek a lot," she said. "I was junior No.1, and ever since I really wanted to play someone who's pro No.1. "That's my goal."