The league don’t actually care, it’s just advised from the aboves for legal purposes. The entire onus is on clubsYeh agree. Not sure how they police it. Unless you declare to the league someone is concussed (which will never happen) then the rule just won’t work.
But clubs leave themselves open to liability if they know a player was concussed and knowingly played them. But the player can also say no.
and if the league don’t get sued it’s a win.