It took nearly the entire month of January, but New York City FC finally made a big move in the winter transfer window, filling a massive hole in one of the league’s top defenses from 2025.
Meet Kai Trewin (pronounced TRUE-win), an experienced and versatile A-League defender widely considered one of the best in the league, and one of the key players in Melbourne City’s title-winning season. Revitalizing a defense that barely squeaked into the playoffs in 2024, Trewin was integral as Melbourne City conceded the fewest goals in the league en route to the club winning the 2025 A-League Grand Final Championship, shutting out Melbourne Victory 1-0.
The move to New York City sparked surprise from the Melbourne City fanbase, who considered the 24-year-old unsellable. But NYCFC Sporting Director Todd Dunivant found a way to pry him away from the club, and now one of the brightest stars to feature in the A-League will be playing in Major League Soccer.
Trewin has just two caps with the Australia men’s national team, and both came late in 2025. With the 2026 World Cup less than six months away, Trewin will be looking to impress head coach Tony Popovic and play himself into the Socceroos squad. The transfer gives the Aussie the ability to showcase his talents on a championship contender in a more competitive league, and in the nation hosting the sport’s marquee international tournament.
To a degree, Trewin joins the Pigeons as Pascal Jansen’s nominal Justin Haak replacement in 2026. But the defender has the potential to be so much more once he settles into the Big Apple.
A true Pascal Jansen archetype
Trewin is a multi-faceted weapon that can be deployed at a variety of positions with equally threatening effect β he’s the perfect Jansen defender.
Trewin broke out with Brisbane Roar of the A-League in 2020, making 118 appearances for the Queensland club before entering the City Football Group ecosystem via Melbourne City FC in June 2024. Operating predominantly from the center of defense, Trewin is a versatile defender who can put in a shift across the back line, yet possesses the progressive qualities to impact the game from midfield as well.
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Kai Trewin, the astute tackler. Credit: Paramount+ Australia
When playing at the back, the Aussie loves to put in a challenge and prides himself on winning the ball, leading the A-League in recoveries (108) among all center-backs in 2025. He also finished in the 78th percentile for successful tackles (32) and 89th for interceptions (27) as Melbourne City conceded the fewest goals in the league last season.
Even this season, Trewin was on another level. In just over 1,100 minutes played in 2025/26, Trewin led A-League center-backs with 693 completed passes and 44 clearances, while sitting in the top 10% for accurate long balls, with 42, and a 50% cross success rate.
John Baney
Excels in attack
However, getting forward is where Trewin is an X-factor.
Trewin bagged three goals and one assist en route to Melbourne City winning the A-League Grand Final, leading all center-backs with the highest xG (3.68), shots (28), and shots on target (10) in the league. If Trewin had those numbers in MLS last year, he would’ve finished Top 3 in every category.
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First of two Kai Trewin goals in a draw vs Western Sydney | Courtesy A-League
The New York City defense excelled in 2025, but failed to score much as a collective, combining for six of the club’s 50 league goals. When Trewin joins the backline, he immediately becomes the squad’s most prolific defensive goal-scoring threat.
Two of his goals came from the penalty spot. But the fact that he was given the ball speaks to his composure and leadership, qualities that bode well for his chances to thrive in this young New York City squad.
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Kai Trewin with the equalizer from the spot in the Melbourne Derby | Courtesy Melbourne City
No defender since Alex Callens in 2022 has scored more than two goals in a single season for New York City, when the Peruvian had five goals in his final campaign in the Big Apple. The Pigeons have lacked a true goal threat from the back since. Trewin changes that. The Aussie offers a threat from set pieces, let alone open play, but also boasts confidence from the penalty spot β a strong skill to have come time for the Leagues Cup and US Open Cup.
Andrew Leigh
Justin Haak 2.0?
When comparing Trewin’s stats with those of former Homegrown defender Justin Haak, the similarities between their games are striking. Trewin surpassed Haak in nearly every attacking metric last season, with the American only seeing an advantage in assists, with four to Trewin’s one. Trewin took nearly double the shots and dished out nearly three times the number of accurate long balls as Haak, though Haak created more chances in the attacking third.
In defense, the stats are closer, with Haak the more adept defender in the air, winning more challenges and clearances with his head, while the Australian excelled on the ground, completing more tackles, blocks, and interceptions per 90 minutes in 2025.
Will Trewin’s game translate from the Australian league to the rough and rigorous gameplay of the MLS? That remains to be seen. He’s set to compete with Raul Gustavo and Thiago Martins for a starting role at center-back, but could foster an impactful relationship with his Australian teammate Aiden O’Neill in defensive midfield.
Added for a transfer fee thought to be at or a bit above $685,000, Trewin may prove to be a shrewd first investment made by Dunivant, if all goes to plan. He has the intangibles to fill the void left by Haak’s departure to LA Galaxy this offseason, along with the potential to push the New York City defense to a new level as the club looks build off a run to the Eastern Conference Final in 2025, and return to the MLS Cup Final for the first time since 2021.
Andrew Leigh
Really interesting acquisition. We have so much flexibility now, it’s actually remarkable. Pascal must be feeling pretty damn good.