Alex de Minaur finished 2018 in a very different position than he started it in. The teenage Australian arrived in Brisbane this year at No. 208 in the ATP Rankings, needing a wild card to get into the main draw of the ATP Tour 250 event.

But that is where De Minaur’s dream season began, reaching the semi-finals. Then it was his first tour-level championship-match appearance in Sydney. The #NextGenATP star had won just two tour-level matches before the year, but he’d earn 28 victories in 2018. And now, after qualifying for the Next Gen ATP Finals in Milan, where he advanced to the final, the World No. 31 is hungry for more.

De Minaur spent a week in early December training under the tutelage of former World No. 1 Lleyton Hewitt and legendary coach Tony Roche — who has worked with Ivan Lendl, Patrick Rafter, Roger Federer and Hewitt — with other Australian players, including John Millman, Marc Polmans and Alex Bolt.

“There are a couple areas in his game he’s got to keep working on and obviously fitness-wise this has been a good year because the past two years he’s had to sort of set himself up for the Australian Open Wild Card Play-off [in early December],” Hewitt said. “You don’t have that many opportunities throughout a year to come together and do a training block and we see this as a massive opportunity to set the tone for the following year, for 2019, and hopefully the guys can see the intensity and the effort.”

De Minaur is known for his speed on the court. And while some players take time to build up their conditioning as they get used to the rigours of the ATP Tour, the Aussie has proven he is fit to compete with some of the best players in the world.

But that hasn’t stopped him from pushing to improve. More than 160,000 people have watched an Instagram video of De Minaur diving to the bottom of a pool, picking up a weight and swimming along the bottom of the pool with it all the way to the other side without taking a breath. It’s safe to say the 19-year-old has an impressive lung capacity.

And while it’s clear De Minaur is working hard, his brother, Dominic de Minaur, says that his sibling’s toughness on court is just part of who he is as a person.

“What you see is what you get with Alex. He’s an incredible young man, he tries his heart out and every time he goes out on the court I know that he’s going to leave it all out there,” De Minaur said. “The way he holds himself and the way he tries on the court, it’s just amazing to watch.”

De Minaur still has two more years as a #NextGenATP player. But he has already earned the respect of his fellow players. Twenty-nine-year-old compatriot Millman, who himself had a breakthrough year in 2018 — reaching a career-high World No. 33 in June — first met De Minaur two years ago during a Davis Cup tie, and he immediately took notice.

“He really impressed me back then. He was a little bit younger then, a little bit more raw. But the way he comes out on court, the enthusiasm he shows, the energy he brings, I think it’s really special. And what he did this year, I thought was incredible,” Millman said. “To come from in the 200s to sit at around 30 at his age, the sky’s the limit for him.”

Watch A Day In De Minaur’s Life:

Now, as the off-season winds down, De Minaur will return to where his breakthrough started, in Brisbane and then Sydney. But this time, all eyes will be on him.

“There’s a lot of media attention around him and playing in those Brisbane and Sydney events leading into the Australia Open, the biggest thing as it gets closer is he needs to embrace it,” Hewitt said. “He’s 19 years old. This is what you want to do. This is a great opportunity to play in some of the biggest events in your home country. He can be playing a lot of those matches on Centre Court with a full crowd behind him, and it’s about embracing it.”

De Minaur is not worried about the hype, and the pressure that comes with his 2018 breakthrough. The 19-year-old is simply focused on taking what he learned and applying it as best he can to continue his climb.

“I have a great team of guys around me that help keep me grounded and focused on the important things in life,” De Minaur said. “I’ve just got to keep doing what I’m doing.”

It’s no secret that the #NextGenATP Class of 2017 took the ATP Tour by storm in 2018. In fact, four players who competed at the inaugural Next Gen ATP Finals in Milan finished this season inside the Top 25 of the ATP Rankings.

Karen Khachanov (No. 11), Borna Coric (No. 12), Daniil Medvedev (No. 16) and Hyeon Chung (No. 25) climbed a combined 152 spots in the Rankings in 2018 and won a total of seven ATP Tour titles. So who might make a jump like that from the #NextGenATP Class of 2018?

Taylor Fritz (World No. 49)
Fritz cracked the Top 50 of the ATP Rankings for the first time this October, but he is not a new face in the tennis world. In February 2016, in just his third tour-level event, Fritz became the youngest American to reach a championship match on the ATP Tour since Michael Chang in 1988. John Isner was the quickest American to reach his maiden final, doing so at his second tour-level event, at Washington, D.C., in 2007.

While Fritz holds just a 1-7 record against opponents inside the world’s Top 10, the American has proven he is capable of competing against the very best in the sport. Fritz has not lost in straight sets against anyone inside the Top 10 in his past six clashes against the elite group, pushing Roger Federer to three sets on grass as an 18-year-old, and extending this year’s Nitto ATP Finals champion, Alexander Zverev, to five sets at Wimbledon just six months ago.

Andrey Rublev (World No. 68)
It’s been clear for the past two years that Rublev is one of the biggest hitters from the baseline on the ATP Tour. But there’s no reason to believe the 2017 Plava Laguna Croatia Open Umag champion cannot continue improving.

Rublev climbed as high as No. 31 in the ATP Rankings earlier this year after reaching the final of the Qatar ExxonMobil Open in Doha. But a lower back injury kept the Russian out for three months, and he was forced to spend the end of the year rounding back into form. Rublev found a good level again in November, finishing in third at the Next Gen ATP Finals. And now that he’s healthy, Rublev can ride that momentum into a strong 2019.

Jaume Munar (World No. 81)
The Spaniard, who is mentored by World No. 2 Rafael Nadal — training at his academy in Mallorca — began 2018 just inside the Top 200 of the ATP Rankings. But he took a major step forward this year, reaching the semi-finals at the Generali Open in Kitzbuhel and making the last four of the Next Gen ATP Finals in Milan.

But perhaps the most revealing victory of his season was in the first round at Roland Garros, where Munar overcame a two-set deficit to beat his idol and clay-court legend David Ferrer. That win showed the world that Munar is not afraid of the big stage, and with plenty of experience gained this year — the 21-year-old earned 10 of his 11 tour-level match wins in 2018 — he can take another step forward in 2019.

Hubert Hurkacz (World No. 87)
The Polish No. 1 might not have been on many people’s radar when he began 2018 as the World No. 238. But Hurkacz had a breakthrough season, going 28-12 on the ATP Challenger Tour and winning his first two titles at that level. He also qualified for the Next Gen ATP Finals, and earned seven of his eight tour-level wins this season.

For those who have not seen Hurkacz play, his game is reminiscent of a young Tomas Berdych. Hurkacz, like Berdych, is 6’5”; he gains control of points with his serve and has relatively flat groundstrokes from the baseline. As the Pole grows older and adds muscle, he will be able to dominate rallies against plenty of players on the ATP Tour.

Reilly Opelka (World No. 100)
Few #NextGenATP Class of 2018 graduates will carry as much momentum into 2019 as Opelka, who won back-to-back ATP Challenger Tour events in Knoxville, Tennessee and Champaign, Illinois to wrap up his 2018 season. Those victories helped the American crack the Top 100 of the ATP Rankings for the first time.

Opelka ranked second on the ATP Challenger Tour this year with a 75.6 winning percentage (34-11), reaching nine semi-finals at that level. Opelka also earned his first win against a Top 10 opponent, beating Jack Sock en route to the quarter-finals of the Delray Beach Open by VITACOST.com. The 2016 Atlanta semi-finalist will look to become a mainstay on the ATP Tour next year.

Catch up on the rest of ATPTour.com’s 2018 In Review series.