The 2005 season saw Syrian clubs join the competition, thus increasing the number of participating countries to 15, and two years later, following their transfer into the AFC in 2006, Australian clubs were also included in the tournament. Owing to the lack of professionalism in Asian football, many problems still existed in the tournament, such as on field violence and late submission of player registration. Many blamed the lack of prize money and expensive travel cost as some of the reasons. The Champions League expanded to 32 clubs in 2009 with direct entry to the top ten Asian leagues. Each country received up to 4 slots, though no more than one-third of the number of teams in that country's top division, rounded downwards, depending on the strength of their league, league structure (professionalism), marketability, financial status, and other criteria set by the AFC Pro-League Committee. The assessment criteria and ranking for participating associations would be revised by AFC every two years.