Group stage A total of 28 clubs were divided into seven groups of four, based on region i.e. East Asian and Southeast Asian clubs were drawn in groups E to G, while the rest were grouped in groups A to D. Each club played double round-robin (home and away) against the other three group members, a total of six matches each. Clubs received three points for a win, one for a draw, and zero for a loss. The clubs were ranked according to points and tie breakers were in the following order: • Points in head-to-head matches among the tied teams; •
Goal difference in head-to-head matches among the tied teams; • Goals scored in head-to-head matches among the tied teams; • Goal difference in all group matches; • Goals scored in all group matches; The seven group winners along with the defending champion (
Urawa Red Diamonds) advanced to the quarter-finals. ;Knockout stage An open draw was held for the knockout stage; teams from the same group or the same association could not be drawn against each other. Each tie was played on a home-and-away
two-legged basis. The
away goals rule,
extra time and
penalty shoot-outs were used to decide the winner if necessary. ==Schedule==