The rapid rise of Kasey Bos is set to continue, with sources telling ESPN that the 21-year-old is nearing a move to Bundesliga outfit FSV Mainz.
The former home of ex-Socceroo striker Nikita Rukavytsya and led by Danish coach Bo Henriksen, Die Nullfünfer finished sixth in the Bundesliga in their past campaign, earning a spot in the Conference League for the 2025-26 season.
Their deal for Bos is expected to be finalised once he completes his commitments with the Socceroos, the youngster called into his first senior national team camp by Tony Popovic for June World Cup qualifiers against Japan and Saudi Arabia.
Elevated to senior status with Melbourne Victory in early 2024, Bos inked a contract extension in February that locked him down until 2026/27 -- ensuring the A-League Men powers will receive compensation for his departure.
In his first season as a consistent first starter, the wingback started 21 of his 23 appearances for Victory across the regular season, grabbing three goals and a further two assists -- two of those goals coming in the final two weeks of the season as Victory locked in a finals spot.
He subsequently netted the opening goal of his side's 2-1 win over Western Sydney in their elimination final and, while missing the second leg of his side's win over Auckland with a heel injury, started in Victory's grand final defeat to Melbourne City.
The disappointment of losing that game was tempered by his first call-up for the Socceroos the subsequent day, named by Popovic -- who was in charge of Victory when he was elevated to the senior side -- as part of an extended 26-player squad.
Not in the 23 named for a smash-and-grab win over Japan, he joined his teammates in flying out to Jeddah overnight ahead of their clash with Saudi Arabia on Tuesday -- the Socceroos only needing to avoid a five-goal defeat to secure qualification for the 2026 FIFA World Cup.
"At the back end of the A-League season, he's been really good, scoring goals", Popovic said on Bos' call-up. "He looks very confident. I know him from my time at Victory. He's really developed a lot over the last three or four years. And I believe he deserves this opportunity."
A former junior at Point Cook and the younger brother of Socceroo and KVC Westerlo winger Jordy, Bos followed in the footsteps of his sibling in beginning his professional career in the academy of Melbourne City, only to be lured to Victory when City relocated their operations to Casey Fields.
He will become the second player from the Victory academy to be acquired by an overseas team since it reformed its youth program, joining Viking FK defender Franco Lino.
While Jordy is currently sidelined with a hamstring injury, Kasey's call-up to the Socceroos moves them closer to becoming part of a select group of brothers to play for Australia's men, with the last pair to take the field together being Joel and Adam Griffiths in a friendly against Ghana in 2008.