Clubs grumbling over international callups is nothing new, but Vissel Kobe's decision last week to deny Japan the services of striker Yoshito Okubo for the Beijing Olympics may prove to be a watershed moment.

The Olympic tournament is restricted to under-23s, with three spaces allowed for players whose age exceeds that limit.

The Japan Football Association, which had already secured Gamba Osaka's Yasuhito Endo to fill one of the overage slots, planned to add the 26-year-old Okubo for the second and leave the final place open in case of injuries before the tournament begins.