He is on the books of Onsala BK and wears shirt number 5. His main role on the pitch is Defender.

His latest transfer saw him join Onsala BK from BK Häcken U19 via on 2017-08-10.

Across the Sweden Cup 2025-2026, Sebastian·Heaver appeared in 2 matches and averaged 0 tackles, 0 interceptions, 0 clearances, and 0 blocked shots per game.