A little over a year ago you could easily find me arguing that Soni Mustivar was the most important player on Sporting Kansas City. Not that he is the best player, he is far from it, but that he is the most important.
In the 4-3-3 system that Peter Vermes prefers the defensive midfielder role is critically important. Look in the clubs recent history and remember back to how important Uri Rosell was to that 2013 MLS Cup Championship team. Observe the drop off that occurred when Uri was replaced by the recently departed (not dead, just traded) Lawrence Olum.