Sinner, Alcaraz, Fonseca all won the Next Gen ATP Finals at 18. Will Justin Engel join them?

Rising teenager Justin Engel will get his shot at the Next Gen ATP Finals following Jakub Mensik’s withdrawal.

The Czech, who won this year’s Miami Open on his way to topping the Race to Jeddah leaderboard, pulled out for medical reasons. Mensik joins 2024 champion Joao Fonseca, second in the standings, in missing the eight 20-and-under player field.

For Engel, could it be the launching pad for a breakout 2026? Last December, that’s exactly how it acted for an 18-year-old Fonseca—following in the footsteps of Jannik Sinner and Carlos Alcaraz when they were the same age.

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Flashback: Introducing Justin Engel, a kickboxer who grew to love tennis

Engel began his year with an opening qualifying loss at an ATP Challenger Tour event in Oeiras. Ranked No. 398 that week, the Nuremberg native would ultimately shave more than 200 spots off his ranking with an evolving game.

His successful transition from ITF World Tennis Tour events to the Challenger level came to life in the fourth quarter of 2025. By then, it wasn’t a surprise to see Engel thriving given his quarterfinal showing at Stuttgart’s ATP 250 grass-court tournament. Seventeen at the time, he became the second-youngest player (Rafael Nadal) since 1990 to earn tour-level wins outside of Davis Cup competition on every surface.

“I definitely notice that the hard work is paying off. When you're compared to big names, it's obviously a great feeling and motivates me to do more!" he reflected with us following that accomplishment.

More undoubtedly arrived by September. Bouncing back from a US Open qualifying loss, Engel advanced to his first Challenger semifinal out of qualifying at Cassis. A second final-four effort followed at the end of the month in Orleans, before clinching a maiden Challenger crown.

Rising to the occasion once again on home soil, Engel twice prevailed in decisive tiebreakers during his Hamburg Challenger run. The youngest Challenger final in 22 years with fellow teen sensation Federico Cina went Engel’s way to vault him inside the Top 200.

“Cina is a big player and I knew before the match it was going to be a tough match. This win makes it even better and I’m really happy,” he said after becoming the first competitor born in 2007 to triumph on the ATP Challenger Tour.

One closing semifinal showing in Bergamo completed Engel’s push up the rankings. For now.