Abdelhamid Sabiri is battling Nurnberg over his desire to leave for England.
The young midfielder is a target for Premier League new-boys Huddersfield Town, who have offered €450,000.
However, Nurnberg rejected the bid and dumped Sabiri to the reserve-team - actions that upset the Germany U20 international.
Nordbayern says Sabiri has refused to train with the U21s as he waits for Huddersfield to up their offer.
The midfielder is tied to Nurnberg until 2019.