Kacper Potulski

At just 18 years old, Polish centre-back Kacper Potulski is taking his first tentative steps into Bundesliga football with 1. FSV Mainz 05. The €2.5m-rated defender has made a solitary appearance this season—playing the full 90 minutes in what represents a significant milestone for the teenage prospect. Mainz currently sit 14th in the table, navigating a mixed run of form (LWWWL) that has seen them oscillate between survival comfort and relegation danger. For Potulski, breaking into a backline that includes the experienced Stefan Posch represents both a challenge and an opportunity. His single appearance, clean disciplinary record, and complete match involvement suggest a composed head on young shoulders—exactly what Mainz need as they look to stabilize their defensive unit. With Poland's rich tradition of producing accomplished defenders, Potulski will be hoping this cameo is the foundation of a long and successful career in German football. The coming months will reveal whether he can force his way into more regular contention.