DEBATE might soon shift to whether a cap should be introduced on the number of people who can comment on the interchange after Melbourne's Nathan Jones became the latest player to chime in with his view.

The chorus of voices however reflects the concern players and coaches have about the potential impact of a cap that AFL CEO Andrew Demetriou said on Tuesday was certain to be introduced in 2014.

With discussion now moving to the appropriate number of interchanges that should be allowed per game, Jones said 80, a figure being trialled in the NAB Cup, was too low.

"I haven't obviously played in it but by the sounds of it from the coaches and the players with the cap it obviously needs to be much higher," Jones said.

"I think it would be almost irresponsible to cap it at 80 if that is the figured that is being bandied around. It's something that we have to get used to but I just think they have to be really smart with the amount of rotations they allow a quarter."

Clubs have expressed concern about the effect on player welfare of a cap and the impact on certain players, but are readying themselves for the change. Many have expressed a view that 120 interchanges per game is a bare minimum.

"There is going to be a greater physical demand on the players there is no doubt about that," Jones said.

"It is hard for me to comment personally because I haven't experienced it yet but the word from the players is that it's extremely tough and considering that it has only been trialled in 20 minute quarters whereas the season quarters may go for 10 or 15 minutes longer the demands are going to significantly increase."