Five ATP players poised to break through in 2026: Nicolai Budkov Kjaer and a new crew

Every ATP Tour season delivers its share of breakout stories—some expected, others out of left field. Whether it’s rising stars knocking on the Top 25, journeymen finally finding their gear, or newcomers bursting into the Top 100, the leaps come in all forms.

As 2026 approaches, here are five players who look ready to level up: where they’ve been, what’s clicking, and why their next move could be big.

Jakub Mensik

In a way, Mensik's breakthrough already happened. The 19-year-old captured a Masters 1000 title in Miami, defeating his idol Novak Djokovic in the final. He been ranked as high as world No. 16, and opponents genuinely fear him in draws. He's only a few improvements away from being a Top 10 staple and a threat to make the ATP Finals next year.

Read More: In beating idol Novak Djokovic, Jakub Mensik came of age in Miami

The 6'4" Czech is currently tied for 11th on tour in hold percentage (85.1%) in 2025, and his first serve ranks among the sport's biggest weapons. Averaging around 130 MPH on his first delivery, he's comfortable ripping serves to any part of the box, which explains why he's second in the world in Ace Rate (16%) this year.

He's equally dangerous following up short returns for plus-one winners, and he's improving his net game consistently. Once Mensik becomes more reliable winning second-serve points, a hold rate approaching 90 percent isn't unreasonable.

Unlike typical big servers, Mensik also brings real baseline prowess. He may look like a classic servebot, but his style resembles Alexander Zverev or Taylor Fritz more than a one-dimensional power player. He'll race through service games but willingly grinds out extended rallies when necessary. Mensik moves well for his size, possesses one of the tour's most dependable backhands, and uses his length well.

To get to the next level, the Czech needs greater consistency from the forehand wing. Opponents target that side too comfortably, waiting out unforced errors. Mensik also must continue improving his conditioning—he occasionally runs out of steam in tougher conditions, allowing opponents to outlast him.

Moving forward, Mensik should be a tough out every tournament he enters. His serve gives him a fighting chance in any set—and, coupled with his baseline toughness, Mensik is poised to become a player with both a high floor and high ceiling.

Hamad Medjedovic

Medjedovic won the Next Gen ATP Finals in 2023 and has slowly built on that success. During his career-best 2025 campaign, the Serbian reached his first ATP final at Marseille's Open 13 Provence in February, reached a career-high No. 57 ranking in August and racked up 17 tour-level wins.

The 22-year-old's aggressive game revolves around dictating rallies early through powerful serving and a heavy forehand that overwhelms opponents. Medjedovic's ability to generate massive topspin off the forehand side is unique. Not many players can flatten forehands out for winners and put that type of shape on the ball.

On hard courts especially, Medjedovic's serve and groundstrokes gain penetration that can stifle opponents—evident in his upset wins over Holger Rune, Karen Khachanov and Daniil Medvedev earlier in the season. He's also proven to be quite good on clay, where he's comfortable sliding and tailoring his approach to take advantage of high bounces.

Medjedovic's challenge will be maintaining a high level consistently. He's somewhat prone to mental and physical breakdowns; perhaps some conversations with Novak Djokovic, who helped fund Medjedovic earlier in his career (Hamad trained at the Novak Tennis Centre), would help. But he has the tools—a big serve and dominant forehand—to became a Top 30 mainstay, and challenging for titles by the end of 2026.

Eliot Spizzirri

In just 10 months, Spizzirri has jumped from No. 738 to a career-high No. 103. The American captured his first Challenger title in San Diego back in February, then added another in Jingshan in September. He carried that momentum into his first ATP quarterfinal run in Brussels a few weeks later, where Spizzirri defeated Alexander Blockx, Pedro Martinez and Botic van de Zandschulp before falling in a tight match against eventual champion Felix Auger-Aliassime.

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The American has always been a tenacious returner, and since 2024 his break percentage at the Challenger level has jumped from 27.1 percent to 28.1. This year, at the ATP level, he's converting 22.1 percent of break chances. That's almost good enough for a Top 20 mark, though he hasn't played enough main-draw matches to appear on the Tennis Abstract leaderboard.

Spizzirri is also improving as a server. He's raised his hold percentage from 74.4 percent in Challenger events in 2024 to 79.1 percent this year, while holding at 81.4 percent at the ATP level. Between that and his improved ability to finish points from the baseline, Spizzirri has very few holes in his game. The American even possesses impressive variety—thanks partly to a 2022 wrist injury that forced him to develop his backhand slice.

For Spizzirri, the next move is cracking the ATP's Top 75, or even Top 50. The 23-year-old has already come a long way as an all-around player; now, he just needs to improve how he handles close matches. That could make all the difference as the two-time ITIA National Player of the Year navigates the leap up from the Challenger Tour in 2026.

Dino Prizmic

Prizmic's big introduction to the tennis world came in a gutsy performance at the 2024 Australian Open, where he pushed Novak Djokovic to the limit in a four-hour, first-round battle. Afterward, the 24-time Grand Slam champion said it was like "playing myself in the mirror."

Read More: What does Dino Prizmic’s possible star-making turn against Novak Djokovic say about both men?

Prizmic has validated that praise throughout an impressive 2025 season, capturing back-to-back Challenger titles in Zagreb and Bratislava without dropping a set in either tournament. Those victories made him the second Croatian after Mario Ancic to win three Challenger titles as a teenager.

The now 20-year-old has posted an impressive 31-13 record across all levels in 2025, and he's been especially dominant on clay courts. That success has propelled him from outside the Top 200 to a career-high No. 115, and he's knocking on the door of a Top 100 breakthrough. Prizmic's 14-match winning streak from May to July showed that he's far too good to be competing at the Challenger level for long.

Prizmic's exceptional ball-striking from both wings separates him from the competition. The 2023 Roland Garros junior champion plays aggressive baseline tennis, combining power with a tennis IQ beyond his years. He's comfortable dictating rallies on clay with heavy topspin, and he's starting to look equally effective on hard courts.

The Croatian simply needs more ATP-level experience, and better luck in the health department. If he can string together a full season of competition, Prizmic has the game to crack the Top 75 early in 2026, and become a regular threat in ATP main draws.

Nicolai Budkov Kjaer

Budkov Kjaer, the 2024 Wimbledon boys' champion, has quietly assembled one of the most dominant Challenger seasons in recent memory after winning in Glasgow, Tampere, Astana and Mouilleron le Captif. The 19-year-old didn't drop a set during his entire Astana run, and in Mouilleron, he dismantled Patrick Kypson 6-0, 6-3 in just 54 minutes—the shortest final in tournament history. As a result, he's rocketed up the rankings from outside the Top 300 at the start of the year to a career-high No. 136.

Read More: Nicolai Budkov Kjaer makes history in winning junior boys' Wimbledon title

Budkov Kjaer already has elite-level weapons in his arsenal. At 6'3", his serve generates significant pace, and Jannik Sinner's coach, Darren Cahill, described his forehand as a "hammer." That big swing can overpower opponents at any level, and he's shown the maturity to close out matches at crucial moments. He just needs to improve his consistency on the backhand wing and build up his rally tolerance a bit more. Once he does, look out.

Budkov Kjaer's success before turning 20 suggests a talent level that should translate to ATP success sooner rather than later. He's also managed by his father, Alexander Kjaer, the former CEO of the Norwegian Tennis Federeration—he has the weapons, work ethic, and pedigree to become Scandinavia's next elite talent.

With his powerful serve, massive forehand, and experience training alongside Sinner and the world's best, Budkov Kjaer isn't just ready to break into the Top 100 by early 2026—he might already have Top 10 potential.