Clubs are set to retain the same list sizes for 2022 while rookies in their third season will be allowed to spend a fourth 'replacement year' on the list after the AFL passed a rule change ahead of the off-season.

Under AFL rules players had not been allowed to spend more than three straight years on the rookie list. However, clubs had been lobbying the League to give extra time to rookies who had been disrupted in their development by the past two AFL seasons by COVID-19.

It saw the AFL confirm to clubs on Wednesday that any player in their third season as a Category A or B rookie will be eligible to spend another season as a rookie in 2022 as a 'replacement' year.

The players will not be required to be delisted and go through the draft process to be re-selected, with the move giving extra time to players brought from international regions or other sports who have had less time to develop at lower levels due to the impact of the pandemic.

But the rule that allowed clubs to move primary-listed players to the rookie list between the first and second list lodgement periods to open up senior spots will not be permitted this off-season.

In a memo to clubs, the AFL said that there is "no forecast changes to list sizes for 2022" and that the one-off rule was brought in last season due to the changes that came late in the piece with list sizes and structures.

They will, however, be able to shift players on the senior list to the rookie list in the time between the national and rookie drafts if the player is contracted for 2022.

Meanwhile, clubs have been told they will have to again select a minimum of three players at the NAB AFL Draft after last year only needing to take one because of list reductions. The three live picks can include promoted rookies (before or after the national draft), national draft picks and pre-season draft selections.

It is a change that signals to clubs ahead of the Continental Tyres AFL Trade Period there will be no more list cuts after last year's numbers fell following the financial impact of COVID-19 on the competition.

The free agency period will run from October 1-8, with the trade period starting on Monday, October 4 to Wednesday, October 13.

The draft will again be staged over two nights, with the League planning for the first round to be conducted on Wednesday, November 24 and the rest of the national draft on Thursday, November 25.

The rookie and pre-season drafts are being slated for Friday, November 26.