The MLS has always been on the cutting edge of change. Whether it was the Penalties to decide games where a player started their run with the ball from midfield in the early days to decide the end of games or their early adoption of VAR. They are constantly tinkering to make the on field product better.
Next year, they will be implementing a few new rules to try to address the widespread issue of "time wasting". Obviously, there are times when a ball should be out of play and we need to wait a little before a restart can occur (Goal Kick, Free Kick, etc.). But on other occasions such as faking an injury or taking a long slow walk off the pitch for substitutions, minutes can run off the clock decreasing the amount of time the ball is actively in play.
The first major change is an "Off-field" treatment rule. This is going to be a massive change to the current playing environment. Unless it has been either a Yellow or Red Card offense, if a player stays down on the ground for more than 15 seconds, then that player must be removed from the field for a minimum of 2 minutes to receive treatment while that players team plays a man down. This rule may eliminate defending teams going down with "cramps" or light challenge resulting in a foul when they are leading at the end of games.
The other major change will occur with substitutions. The timed substitution rule will require players to exit the playing field within 10 seconds when being removed from the game. If they fail to leave the field in the allotted time, their replacement will have to wait an additional minute and enter at the next stoppage. (The rule does not apply for goalkeepers or injury subs.)
Both of these rule changes have been trialed in the MLSNext Pro league for the past 2 seasons. It has been shown to speed up game play, increase the amount of time the ball is in play and decrease perceived premeditated "time wasting".
I think the impacts are going to be massive. First off, who is responsible for counting the 10 or 15 seconds? When we specify an exact amount of seconds (aside from the mythical "6 second rule" for goalkeepers), it will create a situation that requires timely action from the Center Referee or 4th official to be focused on a stop watch rather than what is happening on the pitch. It will create ample opportunity for broadcasters to run stopwatches on the screen to see if the rules are being properly applied. If not, it will be portrayed as incompetence or favoritism for a particular team or both. Will VAR get involved?
Additionally, these rules essentially puts one team on a "power play" even though your team may be have been fouled creating that situation. What if 2 teammates bump knees when making a challenge on a defensive play and go down for more than 15 seconds? Do both players need to go off the field for 2 minutes essentially leaving 1 team with only 8 outfield players until they can be evaluated and cleared to come back in?
I couldn't imagine this in South America where it seems players flail down at the slightest contact for what seems like 50% of the game. On the other hand, this might be exactly what they need. :-)
We'll see how this goes next year. I'm very interested in how this will be applied. I worry that it will put referees and their interpretation of these new rules in the spotlight. That is not something any of us ever want to see.