A total of 40 teams entered the qualification tournament and were drawn into nine groups of five or four teams. West Zone, containing teams from West Asia and South/Central Asia, had two groups of five teams and three groups of four teams, while East Zone, containing teams from East Asia and ASEAN, had two groups of five teams and two groups of four teams. The teams were seeded according to their performance in the previous season in 2012. After playing each other once at a centralised venue, the nine group winners and best six runners-up from all groups qualified for the final tournament.[1]
In order to ensure equality when comparing the runners-up team of all the groups, the results of the matches between the runner-up team and the bottom-placed team (for Groups D, F, G, H and I, which consist of four teams) or two sides from the bottom (for Groups A and B, which consist of five teams) were considered null and void due to Group C and Group E having only three teams participating in the qualifiers.
The best runner-up teams among those ranked second in the groups were determined as follows:
Greater number of points obtained from group matches identified by AFC
Goal difference resulting from group matches identified by AFC
Greater number of goals scored in group matches identified by AFC
Fewer number of points calculated according to the number of yellow and red cards received by the team in the group matches identified by AFC
