The Seattle Sounders have their work cut out for them when they visit StubHub Center in Carson, Calif., on Sunday for a match against their Western Conference rivals the LA Galaxy (1 p.m. PT; ESPN, KIRO Radio 97.3 FM, El Rey 1360AM).

LA may be 2-4-0 on the young season, but Seattle has only won at LA twice in 10 attempts and is coming off a disappointing 2-1 road loss to the Vancouver Whitecaps last Friday. Robbie Keane, Landon Donovan and Steven Gerrard may be gone, but LA has responded by signing longtime United States international midfielder Jermaine Jones and talented French winger Romain Alessandrini.

If the Sounders want to leave Southern California with three points, they must maintain their width, test LA’s back line often and keep Alessandrini out of the middle of the field.

WIDTH, WIDTH, WIDTH

The Sounders utilize a 4-2-3-1 formation with Harry Shipp, Clint Dempsey and Nicolas Lodeiro as the three attacking midfielders beneath forward Jordan Morris. In a configuration that features three central midfielders — Dempsey and defensive mids Osvaldo Alonso and Cristian Roldan — it’s imperative for the two wide players to stay outside. This stretches the opposition and keeps defenders honest, preventing them from collapsing and clogging the middle.

Shipp, Dempsey and Lodeiro, for as talented as all three are, are not accustomed to operating out wide. None is an out-and-out winger. Shipp is an attacking central midfielder by trade, Lodeiro is a traditional playmaking No. 10 and Dempsey is a second striker, which is why he had so much success playing off Jozy Altidore with the United States national team in the most recent World Cup Qualifiers.

Here’s a map of the Sounders’ average position in their loss in Vancouver last Friday.

Shipp (19), Dempsey (2) and Lodeiro (10), in addition to working incredibly close to one another, were vertical rather than horizontal. Lodeiro and Dempsey even overlapped. They were all instinctively trying to play the same position.

Joevin Jones, who, to his credit, is a massive threat outside, saw the ball higher up the field than Shipp. Jones can make plays on the wing, but not if he has to cover the entire side end line to end line.

Here are two examples from the Vancouver match of the Sounders’ attacking trio narrowing the field.

Right back Oniel Fisher has the ball on the right touchline about 15 yards into the Whitecaps’ half. Lodeiro and Dempsey are five yards from one another and in the same passing lane. Shipp, the left attacking midfielder, is inside Morris and making a run to the right corner. This effectively shrinks the field in half.

Here’s another example closer to Vancouver’s net:

Fisher again has the ball on the right side. Dempsey and Lodeiro are each five yards from Fisher to provide passing options, but Shipp again is making a run to support Fisher, while Morris, the lone striker, sinks in behind where Dempsey and Lodeiro would traditionally work.

When Lodeiro eventually does get the ball, his attacking passing options are all but empty. Seattle has made it easy on their opposition to mark men by keeping them so close together. What this does is cut off any passing lanes in behind the center of the defense, the exact area where Morris is so lethal and painfully difficult to defend.

If you look at the successful passes from Shipp, Dempsey and Lodeiro last match, not a single one was connected in the rectangular area stretching from 35 yards away from net to the 18-yard-box.

Being unable to connect any passes in the most dangerous part of the field makes it especially difficult to…

TEST THE GALAXY’S BACK LINE

LA has allowed 10 goals in six games so far, and its only clean sheet came at home against the 10-man Montreal Impact. Jelle Van Damme is one of the league’s best defenders and was a finalist for last year’s MLS Defender of the Year, but the bruising Belgian often has to do the lion’s share of tackling. Daniel Steres and Nathan Smith are young and at times indecisive, and English legend Ashley Cole is 36 years old and far from his former Arsenal and Chelsea self.

Let’s take a look at a play in LA’s match against Orlando City SC last week. Orlando’s Carlos Rivas beats Van Damme on the right side and cuts toward the middle as Steres (5) and Smith (16) back track. Orlando’s Giles Barnes, on the right side of the image, is already visibly calling for a through ball from Rivas as Barnes bee-lines for the gap in between Steres and Smith.

Rivas continues his horizontal run, baiting Steres to step forward, as Barnes, again pointing to the gap in behind, finishes his run.

Rivas sees him and slips an easy touch-pass into the gap for Barnes, whose shot is bravely saved by Clement Diop in goal.

The little slip-pass that Rivas played is exactly what Lodeiro loves to do and what Morris loves to receive. If Lodeiro starts out wide and cuts the ball into the middle — assuming Dempsey and Shipp are occupying space elsewhere —  there should be gaps aplenty for Morris to run into all afternoon.

FORCE ALESSANDRINI OUT OF THE MIDDLE

The Galaxy’s gifted Frenchman has proved one of the league’s best offseason acquisitions so far. He has four goals in his last three games and has been every bit as offensively menacing as advertised.

Similar to the way Lodeiro pulls the strings on the right, Alessandrini loves to cut inside and whip in crosses or fire shots with his favored left foot. In LA’s formation, he has room to pick his moments to come inside and disrupt defensive shapes. Here is LA’s projected lineup on Saturday:

Jones and Joao Pedro fill the center of the park, but Alessandrini often pinches inside ahead of both and behind a withdrawn Giovani dos Santos. When Alessandrini does that, it takes defenses a moment or two to adjust and step up on him, but by the time they have figured it out so far this year, they’ve been picking the ball out of the back of their net.

Here is Alessandrini’s goal in LA’s win over the Impact two weeks ago. Emmanuel Boateng has the ball wide to the left. As Montreal sinks in, Alessandrini (far right) has darted toward the middle and is signaling to Boateng to drop the ball into the space midfielder Marco Donadel has voided in his retreat.

Boateng sees Alessandrini and sets the ball on a platter for him to one-time past Evan Bush.

Here’s another example against the Vancouver Whitecaps earlier in the year, almost a carbon copy of the goal against Montreal. Jack McBean springs Boateng loose on the left side again. Boateng calmly curls in a cross to the center of the box that an onrushing Alessandrini rockets home.

Stopping Alessandrini isn’t the only thing the Sounders have to worry about defensively, but if someone like Alonso can clog the middle and prevent Alessandrini from running unabated in the center of the field, the Sounders should feel pretty good about their chances this weekend.