Perceptions of the Sounders have evolved significantly over the course of the season. Early in the year many people questioned whether Eddie Johnson could still score goals. Later, when it was clear that EJ found his shooting boots, there were concerns that Fredy Montero could not play alongside him. Now that Fredy has found his form, the production of the Sounders' forward tandem is only surpassed by San Jose and New York.
Both EJ and Fredy owe much of their recent goalscoring form to the distribution of Mauro Rosales. While he has been fantastic of late, the diminutive Argentinian has gone through his own struggles this season. Some of these struggles can obviously be attributed to injury and fitness issues. There has never been a shortage of MLS defenders willing to put Rosales on his backside, but if you look deeper into the numbers you will find that this is perhaps not the only reason for Rosales's early season dip in form.
When analyzing personnel and tactics, it quickly becomes apparent that Rosales has performed notably better when Adam Johansson is on the field. In the twelve games that both players have significant minutes, Rosales has eleven assists. In the seven games that Rosales has been paired with Zach Scott, Rosales has contributed just two assists. While some of this effect is likely due to injury, form, and chance, the correlation is too strong to ignore. Rosales and Johansson's styles fit well together and the Sounders are simply more dynamic in the attack with both players on the pitch.
In order to understand why Johansson is the better option, you need to understand how the fullback position has evolved in recent years. Prior to the new millennium, most managers looked for fullbacks that were solid defensive players with little talent or inclination to get forward. The limited offensive capabilities of these players was never a concern for managers. However, this changed dramatically in the early part of the 2000s. In England, Arsene Wenger is generally credited with introducing the attacking fullback. Instead of accepting the limited offensive skills of the fullbacks he inherited, Wenger took a promising forward prospect (Ashley Cole) and a midfielder (Lauren) and converted them into the attacking defenders his system required.
Wenger understood several things about fullbacks that English managers were overlooking. First, fullbacks are often the only players that find themselves consistently open in space. Opposing wide midfielders generally marked each other out. With no players assigned to mark the fullbacks, they were often in positions to both receive the ball in space and move forward. This is particularly true when your wide midfielders drift towards the center of the pitch. In such cases, it is vital for the fullback to provide width to your attack. This is precisely the role that Johansson plays for the Sounders.
If you've ever looked at Rosales's heat maps, you will see that he spends almost as much time in the center of the pitch as he does along the touchline. When Rosales drifts into the center, Johansson naturally moves into the space Rosales vacates. Although this provides Rosales with a wide passing option, it also forces the defense to remain honest. Because Johansson is a legitimate offensive threat, opposing defenses cannot close down Rosales without leaving Johansson in dangerous positions. With defenses now forced to commit a player to watching Johansson, Rosales has been finding himself with much more room to operate. With this space, Rosales has been able to find the passes needed to open opposing defenses.
It is not just when Rosales drifts forward though. Johansson is very good at picking his spots to make overlapping runs--a tactic that can confuse opposing fullbacks and pull the defense out of shape. With the defense disorganized, a player as adept as Rosales will be able to find the killer pass. At times this could be feeding the wide run of Johansson--at other times it will be looking for EJ or Montero in the center. Regardless of his choice, it was set up by the pressure applied from the right back position.
Zach Scott brings a completely different skill-set to the table. While Scott does some nice things defensively, and is even an effective target on set plays, nobody would claim he is offensively gifted. He has limited ability to overlap and both his passing decisions and accuracy are poor. With Scott presenting a limited threat going forward, opposing defenses can concentrate more of their efforts on Rosales. Essentially, opposing defenses compact the field by cheating inside. With less space to operate, Rosales will find fewer passing options available. In such circumstances, it should not be surprising that Rosales's performances would suffer.
Although the statistics almost certainly overstate the effect of Johansson, they are strong enough to show that an attacking fullback is important in this system. It is pretty clear that Rosales remains the creative engine of the Sounders attack. Without a similar fullback on the roster, the health of Johansson is now critical to any title aspirations the Sounders possess.