Ono expressed his desire to play in Athens. Yamamoto being the softy that he is will probably feel sorry for Ono that he missed the olympics last time and let him join.
Does the U-23 need a player like Ono? I guess he can provide good leadership, and he really does deserve to go - the playmaking combo of Nakamura and Ono was simply amazing and that injury was just devastating. Also, since Zico announced that the Olympic team has priority over the Asian Cup, maybe Ono's trying to avoid the full national team?