Rasmus Niklasson

He started his youth career in Sävedalens IF before moving on to Bälinge IF in another part of Sweden, outside Uppsala. In 2019 he even started his senior career in Bälinge, before moving to the academy of IK Sirius. Here he played for their U17 and U19 teams. His first major senior club was Dalkurd FF in 2023, where he scored four goals. Having gone on to Ettan club Oskarshamns AIK in 2024, he had scored the same number of goals three months into the season. Now, interest was shown from larger Swedish clubs. In the summer of 2024 he agreed to move up two divisions, transferring to GAIS. As Oskarshamn struggled in the table, the transfer was postponed to the winter of 2025. He scored on his GAIS debut, a 2024–25 Svenska Cupen match against Örebro.

He was formerly named Johansson, but changed his surname to Petrovic alongside the rest of his family.