Lately the Sounders have been using a kind of 4-2-3-1. It is similar to the Arrow that we used to note around here, and has primarily been the way that the Sounders have dealt with the loss of Brad Evans to injury. Nathan Sturgis doesn't play forward as much as Evans, but he also doesn't get back as much as Alonso.
He's probably the best to play this hybrid CDM/CM, but he wouldn't be starting if the team was at full health.
Seattle also likes to use two wingbacks rather than a flatter four. With two capable, but incomplete backups, at the Leftback and one possible at Rightback these days (Scott) all of these though force a change in tactics as they are not able to get forward like either of Leo Gonzalez and James Riley. Leo's short game on the left, and James' service on the right create a kind of imbalance to the offense, but considering MLS salary structure I don't find this an issue. The issue as pertains to this discussion is that Riley's defense is a bit error prone - enough so that there were thoughts in these parts that maybe he should be the second CDM, moving Alonso into more of a deep-lying playmaker role, or as the Right Midfield creating further imbalance.
The addition of Alvaro Fernandez initially was thought to be a CM or maybe a CAM/Playmaker. This was due to the large amount of depth at Right Wing/Mid on the team (Montano, Nyassi, Estrada, Jaqua, Fucito, Levesque), and some of it has been due to the search for an adequate playmaker or focal on offense. Since he's moved to being the other Winger, the lack of a kind of playmaker becomes more apparent.
In light of Wilson's recent writings on the Playmaker I reawakened to the idea that Seattle's needs, maybe only due to injury are for a CM/CAM in the old Arrow.
And so I'm wondering where you think the biggest hole in the formation is? Is Sigi really trying to play a 4-4-1-1 (with two holding mids) or is his goal to get back to a the Arrow but that he lacks the CM for it?
Or is Seattle at its weakest at the Right Back? I have even read some state the Left Back is the weakest.
The Roster Freeze deadline is Sept 15th, so Seattle can still add Frees, or trade within the League.