Former Newcastle and Aston Villa winger Charles N'Zogbia could be forced into retirement.
The Sunderland Echo says N'Zogbia's bid to revive his career in France has been rocked by reports he has suffered a 'heart complication'.
N'Zogbia trained with Sunderland in the summer after being left as a free agent following his departure from Aston Villa.
Ouest France says a move to Nantes is off after doctors confirmed that the heart complication picked up in an initial medical earlier this week is too severe for Les Canaris to be able to sign the player without significant risk attached to the player's present and future health.