A total of 28 clubs are divided into 7 groups of four, based on region i.e. East Asian and Southeast Asian clubs are drawn in Group E to F, while rest are grouped in Group A to D. Each club plays double round-robin (home and away) against fellow three group members, a total of 6 matches each. Clubs receive 3pts for a win, 1pt for a tie, 0pts for a loss. The clubs are ranked according to points and tie breakers are in following order:
Points earned between the clubs in question
Goal Differential between the clubs in question
Goal For between the clubs in question
Points earned within the group
Goal Differential within the group
Goal For within the group
The seven group winners along with the defending champions qualifies to the quarter-finals.
All 8 clubs are randomly matched; however, the only restriction is that the clubs from same country cannot face each other in the quarterfinals. The games are conducted in 2 legs, home and away, and the aggregates goals decides the match winner. If the aggregate goals cannot produce a winner, away goal rules in used. If still tied, clubs play extra time, where away goal rule still applies. If still tied, the game goes to penalties.
1 On April 20, following the match between Al-Qadisiya and Al-Sadd, Kuwaiti security personnel assaulted the visiting players; Al-Qadisiya were ejected from the competition and banned from AFC competitions for three years. Their record was expunged.
1 Al Ahly withdrew following the decision by the Bahraini FA to retain 7 of their players for the national team and Olympic squads for their World Cup and Olympic Games qualifying matches; no penalties were imposed.