Cassisi warned players' bodies will not cope with the bench limitations, while Sanderson declared the cap could change completely the face of the game.
From 2014, the league has confirmed it will limit the number of bench rotations to just 80 per side per game, a move which has been trialled in this year's NAB Cup pre-season competition.
And while AFL chief executive Andrew Demetriou bluntly declared the cap was going to happen and that players and coaches should "get used to it", the backlash against the new restrictions continued on Tuesday.
Sanderson said the cap could change the way clubs approach the draft and threatens to force out some of the game's most explosive small forwards, who rely heavily on rotations.
"It'll certainly affect the way we pick players at the draft and certainly affect how we train," Sanderson said.
"We'd need more players between the heights of 188 and 192cm with a really good aerobic capacity.
"Guys like (Crows forward) Jared Petrenko, who's just flat out for five minutes and then off, would probably find it harder to get a game."
The reaction was just strong from Crows' arch rivals Port Adelaide, with veteran former skipper Cassisi warning the cap would re-invigorate the flood.
Cassisi joins his coach Ken Hinkley in outspoken opposition to the ruling, with the new Port mentor claiming the cap defies common sense.
Earlier on Tuesday, league boss Demetriou declared to Melbourne's SEN radio that the AFL would not budge on the cap.
"The fact of the matter is unless people have got amnesia the AFL Commission has already passed the rule, which it said at the end of the year the cap's coming in," Demetriou said.
"There's no going back on that. That's already been in place.
"I'm not quite sure why after one round of NAB Cup, everyone's up in arms, they want it reviewed."
The cap has come under heavy criticism so far during the pre-season competition, from new Carlton coach Mick Malthouse, Hawthorn's Alastair Clarkson and North Melbourne coach Brad Scott.