Former WBO Minimumweight champion Ryuya Yamanaka (16-3, 5) apparently suffered a nasty injury in his loss to Vic Saludar (18-3, 10) back in July. The injury apparently won't have long term problems but will force him to retire, at the age of 23 A real shame, thought he looked sensational against Calleros, and had the potential to be one of the faces of the Japanese scene, but then to have to retire only a few months later must be crushing. Source Ryuya Yamanaka to retire following subdural hematoma