Mainz 05 announced on Friday that 21-year-old Australian left-back Casey Bosz has joined from Melbourne Victory on a four-year contract until June 30, 2029.

German Sky Sports reporter Florian Plettenberg further pointed out that Bosz's transfer fee was 500,000 euros.

Casey Bosz grew up in the Melbourne Victory youth training system and made his debut for the first team in the Australian Super League on February 25, 2024. So far, he has played 35 games for Melbourne Victory, contributing 5 goals and 3 assists.

With his stable performance at the club level, Bosz was selected for the Australian national team for the first time earlier this month. However, he failed to get a chance to play in Australia's 2-1 World Cup qualifier against Saudi Arabia.

Regarding Bosz's arrival, Mainz sports director Nico Bongert commented: "Kathy Bosz is a left-wing player with excellent running ability, both offensive and defensive, and a positive and brave style on the field. He is exactly the type of player we are looking for."

"He has shown his talent in the A-League. We believe he has the potential to establish himself in the Bundesliga and develop well alongside experienced players such as Philip Mwene."

Bosz said: "The conversation with the management was very pleasant and the city itself left a very cool impression on me. The Bundesliga is very attractive to me and the competitive level is very high."

“My Melbourne team-mate Michael Langerak has already given me a lot of advice. I am now looking forward to getting to know the team and the fans as soon as possible and exploring Mainz further.”