Okay, there's just no way around this one. The UEFA Champions League is the premier club competition on the planet, therefore, it attracts the best players in the world to the top European domestic leagues. In an age where every player is seemingly on the move to the highest bidder, every conversation about a top talent ends with, "surely he'll be looking for Champions League football next season." That's just the way it is, and while CONCACAF Champions League and Copa Libertadores are on the rise as American continental tournaments, there is only one UEFA Champions League. It is for the foreseeable future, an obstacle MLS will have to overcome in it's quest to sign superior players and gain respect globally.
Con: No UEFA Champions League Football