AFL Teams can have a maximum of 47 players on their list. The AFL has a two tiered list sytem with a "primary list" and a "rookie list". The difference between the two is that a side can only play a certain number of rookies each game (these restrictions are not imposed in preseason games). The number of rookies a side can play varies with reference to the team's primary list size and any long term injuries, with rookies being "promoted" to the primary list to cover a main list player with a long term injury (in excess of 12 weeks).
Team's can manage their list size depending on their age profile, salary cap profile or injury profile. A side must have between 38 and 40 primary list spots and fills up the remaining with rookies.
Pre season competitions are usually used to blood rookies and young players who would not ordinarily be in the side's best 22.
