Talk:Gameplay/@comment-2234004-20140309134259/@comment-2234004-20140309192810

The quick guide isn't too specific; it just says that since the size is now over 3, to retire the monster(s) from before, hinting that you place the card in "limbo" before finally calling it.

So, select a monster, place it in "limbo" (this is where call negation can activate), check the total size, retire the extra, finish calling it.

That's how I see it anyway.