Mrowca joined the youth ranks of German record champions Bayern Munich at the age of ten in 2004. Later he became captain of their U19 team. During the 2012–13 Regionalliga season he was promoted to their reserve team. He didn't make any appearance but was on the bench for three times.
On 26 June 2023, after nine years at Wehen Wiesbaden, Mrowca moved to 3. Liga club SC Preußen Münster. He left the club upon the expiration of his contract in June 2025.