He currently plays for Helsingor, wearing the number 2 shirt. He plays primarily as a Defender. His preferred foot is Both. His current market value is estimated at 150K .

His most recent move was a from Hillerod Fodbold to Helsingor on 2025-02-07.

Throughout the Danish 2nd Division 2024-2025, frederik karlsen featured in 12 matches, averaging 0 tackles, 0 interceptions, and 0 clearances per game, while blocking 0 shots per game.