As pre-season training and roster preparations are dominating the news here in Portugal, where I live, I took a couple minutes to review this claim that MLS rosters are paper thin.
The gold standard for rosters in Europe is two players per position for the main squad. That means 20 outfield players and then possibly 3 keepers; so 23 players. At first glance the 24 squad limit in MLS doesn't seem very shocking. Ofcoarse in MLS there is the chance to replace a player with a season long injury which in european soccer (atleast in portugal) is not an option.
In Portugal, for practice purposes, when a player is injured a member of the youth squads is usually promoted to full the void that would be left if the squad has drills that are specific to a certain number of players. So here TFC is ok because there is the youth academy that could probably fulfill this role.
In england I know there is an entire "B" league where teams field their unused players and possibly meaning that there is a second squad beyond the 23 players in the first squad. (Not sure about the specifics here, just pointing out the fact that there is a B league in england).There used to be a B league in Portugal but it was abolished many years ago.
Are there more games in MLS making the same roster numbers overworked? In Portugal there is the league, the cup, the league cup and for top teams europe (Champions league, eufa cup (europa league), or the intertoto cup). There is no shortage of competitions. During the year a successful team which makes a competitive run in the cup, league cup and europe (obviously they have to play all league games regardless of performance) you will play 2 games a week guaranteed all season.
So what is the problem? I believe there are 2.
1) tactical advantage to having a short squad - The salary cap puts teams in a position to face a decision of having a short squad to invest more money into less players. Trying to get more quality into the starters at the cost of not having a full squad. TFC right now has 21 players which is 2 below the gold standard I referred to. (Although they have 2 goalies probably because they know if one is injured they are allowed to get someone else).
Realistically though all teams around the world have a budget. All teams except maybe the worlds biggest would have to think about whether they spend big bucks on key players or spread the money over depth.
2) MLS doesn't schedule around FIFA fixture dates - This clearly handcuffs teams because the number of available players starts to dip ridiculously below the 23 when there are international call-ups.
The roster rules seem fine to me. Nothing beyond what is normal in international soccer. If they could just schedule around FIFA it'd be golden.