Jeonbuk Hyundai Motors were the defending champions, but they were excluded from the 2017 season due to a bribery scandal in the domestic K League Classic. Jeonbuk appealed to the Court of Arbitration for Sport, but their request for provisional measures was rejected on 3 February.
Association team allocation
The AFC Competitions Committee proposed a revamp of the AFC club competitions on 25 January 2014, which was ratified by the AFC Executive Committee on 16 April 2014. The 46 AFC member associations (excluding the associate member Northern Mariana Islands) are ranked based on their national team's and clubs' performance over the last four years in AFC competitions, with the allocation of slots for the 2017 and 2018 editions of the AFC club competitions determined by the 2016 AFC rankings (Entry Manual Article 2.2):
In each region, there are four groups in the group stage, including a total of 12 direct slots, with the 4 remaining slots filled through play-offs.
The top 12 associations in each region as per the AFC rankings are eligible to enter the AFC Champions League, as long as they fulfill the AFC Champions League criteria.
The top six associations in each region get at least one direct slot in the group stage, while the remaining associations get only play-off slots (as well as AFC Cup group stage slots): The associations ranked 1st and 2nd each get three direct slots and one play-off slot. The associations ranked 3rd and 4th each get two direct slots and two play-off slots. The associations ranked 5th each get one direct slot and two play-off slots. The associations ranked 6th each get one direct slot and one play-off slot. The associations ranked 7th to 12th each get one play-off slot.
The maximum number of slots for each association is one-third of the total number of eligible teams in the top division.
If any association gives up its direct slots, they are redistributed to the highest eligible association, with each association limited to a maximum of three direct slots.
If any association gives up its play-off slots, they are annulled and not redistributed to any other association.
For the 2017 AFC Champions League, the associations were allocated slots according to their association ranking published on 30 November 2016, which takes into account their performance in the AFC Champions League and the AFC Cup, as well as their national team's FIFA World Rankings, during the period between 2013 and 2016.
The slot allocation was announced on 7 December 2016, with India and Maldives returning to the West Region. The final slot allocation, after unused slots were redistributed, was announced on 12 December 2016.
The following 47 teams from 19 associations entered the competition.
In the following table, the number of appearances and last appearance count only those since the 2002–03 season (including qualifying rounds), when the competition was rebranded as the AFC Champions League.
Location of teams of the 2017 AFC Champions League. West Region East Region (p) Qualifying play-off participantsLocation of the 2025–26 AFC Champions League Elite league stage teams Blue: West Region
Schedule
The schedule of the competition was as follows. Starting from 2017, matches in the West Region were played on Mondays and Tuesdays instead of Tuesdays and Wednesdays.
In the qualifying play-offs, each tie was played as a single match. Extra time and penalty shoot-out were used to decide the winner if necessary (Regulations Article 9.2). The eight winners of the play-off round advanced to the group stage to join the 24 direct entrants. All losers in each round from associations with only play-off slots entered the AFC Cup group stage. The bracket of the qualifying play-offs for each region was determined by the AFC based on the association ranking of each team, with the team from the higher-ranked association hosting the match. Teams from the same association could not be placed into the same play-off.
The draw for the group stage was held on 13 December 2016, 16:00MYT(UTC+8), at the Hilton Petaling Jaya inPetaling Jaya,Malaysia.The 32 teams were drawn into eight groups of four: four groups each in the West Region (Groups A–D) and the East Region (Groups E–H). Teams from the same association could not be drawn into the same group. In the group stage, each group was played on a home-and-awayround-robinbasis. The winners and runners-up of each group advanced to theround of 16of theknockout stage.
Tiebreakers
The teams were ranked according topoints(3 points for a win, 1 point for a draw, 0 points for a loss). If tied on points, tiebreakers were applied in the following order (Regulations Article 10.5):Points in head-to-head matches among tied teams; Goal difference in head-to-head matches among tied teams; Goals scored in head-to-head matches among tied teams; Away goals scored in head-to-head matches among tied teams; If more than two teams are tied, and after applying all head-to-head criteria above, a subset of teams are still tied, all head-to-head criteria above are reapplied exclusively to this subset of teams; Goal difference in all group matches; Goals scored in all group matches; Penalty shoot-out if only two teams are tied and they met in the last round of the group; Disciplinary points (yellow card = 1 point, red card as a result of two yellow cards = 3 points, direct red card = 3 points, yellow card followed by direct red card = 4 points); Team from the higher-ranked association.
In the knockout stage, the 16 teams played a single-elimination tournament, with the teams split into the two regions until the final. Each tie was played on a home-and-away two-legged basis. The away goals rule, extra time (away goals would not apply in extra time) and penalty shoot-out were used to decide the winner if necessary (Regulations Article 11.3).
Bracket
The bracket was decided after the draw for the knockout stage, which was held on 6 June 2017, 16:00 MYT (UTC+8), at the JW Marriott Hotel Kuala Lumpur in Kuala Lumpur, Malaysia.
In the round of 16, the winners of one group played the runners-up of another group from the same region, with the matchups determined by the group stage draw, and the group winners hosting the second leg.
The draw for the quarter-finals was held on 6 June 2017. In the quarter-finals, the four teams from the West Region played in two ties, and the four teams from the East Region played in two ties, with the matchups and order of legs decided by draw, without any seeding or country protection.
In the semi-finals, the two quarter-final winners from the West Region played each other, and the two quarter-final winners from the East Region played each other, with the order of legs determined by the quarter-final draw.
In the final, the two semi-final winners played each other, with the order of legs (first leg hosted by team from the West Region, second leg hosted by team from the East Region) reversed from the previous season's final.
