He is on the books of Sportfreunde Lotte and wears shirt number 39. His main role on the pitch is Defender. He measures 183cm in height and weighs 78kg. His estimated market valuation currently stands at 50K €.

His latest transfer saw him join Sportfreunde Lotte from SV Rodinghausen via on 2025-06-30.

Across the German Regionalliga 2025-2026, J. Riemer appeared in 20 matches and averaged 0 tackles, 0 interceptions, 0 clearances, and 0 blocked shots per game.