changes that help grow the sport.

Its a simple rule that players who are accustomed to faking (e.g., to waste time or get some extra rest or to trick the ref into a harsher call against opponent) will dislike.

A regular player who is not a mega-millionaire like Messi and who doesn't base their game on injury faking isn't going to be overly upset by the rule. For a standard MLS player if they want their league to grow and increase in popularity then they could support the rule in their own self-interest - would lead to more interest, better tv deals, and better player salaries.

Of course a guy like Messi who has lived his life in soccer-obsessed countries is going to be more against rule changes. He and people from his countries already think the sport is perfect; unfortunately, average american and average american sports fan sees obvious ways to improve the game and to disincentive flopping and faking. So bravo to MLS leaders on this one to use the rules to improve the game.