VVV-Venlo midfielder Keisuke Honda and Catania striker Takayuki Morimoto were named on Monday to headline Japan's Olympic football squad, which has no overage players due to injuries.
Coach Yasuharu Sorimachi said he put players' hunger to win before technique and physical fitness when selecting the 18-man squad.
The most important thing was "tenacity and perseverance and not giving up until the last moment," he told a press conference.
"I chose these 18 players to showcase Japanese football in Beijing. First and foremost, I want to pour all our efforts and focus into going through the group round," he said.
However, Endo and other candidates for the overage spots have struggled with injuries and illness. Each squad of 18 is allowed three players over the age of 23. The squad will play friendlies with Australia on 24 July and reigning Olympic champions Argentina on 29 July.
Goalkeepers: Kaito Yamamoto (Shimizu S-Pulse), Shusaku Nishikawa (Oita Trinita)
Defenders: Hiroki Mizumoto (Kyoto Purple Sanga), Yuto Nagatomo (FC Tokyo), Masato Morishige (Oita Trinita), Michihiro Yasuda (Gamba Osaka), Atsuto Uchida (Kashima Antlers), Maya Yoshida (Nagoya Grampus)
Midfielders: Takuya Honda (Shimizu S-Pulse), Hiroyuki Taniguchi (Kawasaki Frontale), Yohei Kajiyama (FC Tokyo), Hajime Hosogai (Urawa Reds), Keisuke Honda (VVV-Venlo/NED), Shinji Kagawa (Cerezo Osaka)
Forwards: Yohei Toyoda (Montedio Yamagata), Tadanari Lee (Kashiwa Reysol), Shinji Okazaki (Shimizu S-Pulse), Takayuki Morimoto (Catania/ITA)