Mrozek started training at
MKS Kluczbork. In 2017, he joined the FC Wrocław Academy. He signed for
Premier League side
Liverpool in July 2020, and featured for the club in the
2021–22 UEFA Youth League. His unofficial first-team debut came on 15 July 2022, playing the last 10 minutes of a 2–0 friendly win against
Crystal Palace. On 26 July 2024, Mrozek extended his contract with Liverpool and was sent on a six-month loan to
Allsvenskan club
Brommapojkarna. He made his debut the following day, in a 3–4 away league win over
IFK Göteborg. On 4 February 2025, he joined
National League side
Forest Green Rovers on loan until the end of the season. Hours later, he made his debut starting in a 0–2 away win over
Dagenham & Redbridge. On 5 March 2026, Mrozek signed with
Major League Soccer side
FC Cincinnati on loan for the
2026 season, with an option to make the move permanent. ==International career==