Normally figuring out the lineup for a Bruce Arena-coached team isn't too complicated. He's not really a tinkerer, though last season LA did spend a couple of months in a diamond before going back to the 442 they won MLS Cup with. There may be a question here or there, but generally things are straightforward.
That's not the case this week for D.C. United, who have to figure out who will start for an LA Galaxy side missing Robbie Keane, Gyasi Zardes, and Jaime Penedo from their best eleven (not to mention Bradford Jamieson IV and Oscar Sorto for youth national team duty). There are some interchangeable parts here, and it makes for a somewhat cloudy picture. It's even less clear once you factor in AJ DeLaGarza's recovery from a foot bruise - one that has seen him make the bench but barely play outside of a Galaxy II start - and Edson Buddle being less than fully fit.
One change from last year has been pretty clear: The flat 442 has been dropped thanks to the departure of Marcelo Sarvas (and possibly because teams are more willing to attack a team missing the retired Landon Donovan). LA is now dropping Juninho underneath the rest of the midfield in possession, which is more Y-shaped than anything else. This isn't that different from last year; rather, it's just more pronounced.
In the back, things aren't complicated. On the right, Dan Gargan probably has an edge over DeLaGarza as the ex-Maryland Terrapin is apparently not fully fit just yet. Even if he is, Arena may prefer to bring him in as a replacement for Leonardo, who continues to be Leonardo. Arena may see Bobby Boswell and Steve Birnbaum as enough of a threat on set pieces - where Houston scored their goal last week - to consider keeping Leonardo in, but in the run of play at least Leonardo would be a liability.
Robbie Rogers will almost certainly stay at left back, but with Jose Villarreal sounding like a probable starter up front instead of in the midfield, there's at least a sliver of a chance that Rogers moves up and is replaced by Todd Dunivant. I think LA is invested in continuing to use Rogers as a left back - where he still hasn't actually played a full season's worth of games - but they're short enough elsewhere that a one-game move may cross Arena's mind.
Juninho will drop off, particularly if United doesn't make any alterations to their normal approach position-wise. That means some extra work for Chris Pontius dropping off the front line, as Juninho is among the most relied-upon players in MLS. LA counts on him to collect the ball off the back four and to connect 60-70 passes a game; if he's allowed time, he'll dictate the tempo of the game. Let LA control that, and United is looking at a problem.
Husidic has done well enough since curiously not starting the season opener (Arena went with Kenney Walker, who was not comfortable having to play higher up the field), but Villarreal's move up front pretty much leaves him as the only option on that side. Jamieson would also be in line, though he's not really a natural on the wing either. If Villarreal stays in the midfield, he'll look to move inside either for combinations or on the dribble. Husidic will take up less aggressive positions, but he's a big threat to burst into the box late.
If Husidic is on the left, that means newcomer Mika Vayrynen will probably get the start ahead of Walker (who wasn't even in the 18 last week) in central midfield. United should be checking in with Markus Halsti for a scouting report, as Vayrynen is also a member of the Finnish national team. He's only appeared as a substitute so far, but he's looked sharp in both appearances. He has so far seemed comfortable as a traditional #8, and I'm impressed with his technique as well. I'm not sure he's the force inside the box that Husidic is, but he seems like he has a knack for finding loose balls at the top of the box. Small sample size is a big factor here, as I only know Vayrynen from two MLS substitute appearances and through Football Manager (which is super fun but can be inaccurate with real-life players).
The Galaxy midfielder to watch defensively is Stefan Ishizaki, who LA is looking at to become a significant creative force. With Keane out and LA possibly playing Alan Gordon and Edson Buddle, shutting Ishizaki down is going to be be job #1 to keep the Galaxy from creating any good chances. The Swede is a gifted crosser, but is also capable of looking inside to play through the defense as well. He's not a showy dribbler of the ball, but he is good enough to give himself enough space to get the cross or pass away.
Up front, Gordon is a definite starter. He's the same player he ever was: Hard-working, good in the air, and he's not terrible at holding the ball up to find others. Of course, without Keane receiving those lay-offs, "not terrible" might be something United can exploit. Gordon is a good complimentary player, but with LA's absences he'll have to carry more weight than usual.
The other forward is probably going to be Villarreal, who would play underneath and offer the more technical side of the partnership. However, LA could also opt for giving Buddle 55-60 minutes. Given how long balls right at United's central defense have worked too easily for comfort this season, LA may be tempted to play two #9s. Neither player has the speed to break through in pursuit of a through ball, but the gaps Boswell and Birnbaum have been leaving are still alarming. This brings us back to shutting Juninho down, but we'll get into that later today.
As for subs, Buddle will probably get into the game off the bench. We could also see young players like Ignacio Maganto or Raul Mendiola, particularly if LA is pursuing a goal. If they're trying to shut things down, players like Walker and Dunivant are more likely to figure in.