Every season in MLS, there's going to be one team that is very difficult to write these scouting reports about. Usually the issue is a tinkering manager who has a transparently obvious best eleven but can't resist the idea that he's a tactical genius, and that his tinkering from one game to the next will make all the difference. John Hackworth was guilty of this, and years before him there was Juan Carlos Osorio.
The problem with these guys is that MLS is sort of a tactical Goldilocks league: Teams that play old-fashioned English-style 442 soccer tend to underachieve, while the managers that like to pretend they're in Serie A by fielding inverted fullbacks, central wingers, and false 9s tend to fail because they've overcomplicated things. The bosses that get the most out of their roster tend to be the ones that take a simple plan and add a wrinkle here or there.
Pablo Mastroeni's tenure has seen some examples of trying to be too complicated, but not for the typical reason. Mastroeni's Rapids have settled on a style, but they're all over the place when it comes to formations and who starts. Colorado's squad is full of positionally flexible players, so even given a list of starters there are no guarantees. I try to keep tabs on all the recent formations played by teams around the league, but for the Rapids this means I have to watch the start of every single one of their games to know what they're up to.
Of late, the Rapids seem to be going back and forth between a 4231 and - now that Jose Mari is back fit - a 4132 (before that, they played a 4312, which is only marginally different). There can be a reason to do this, as seen with the Vancouver Whitecaps. You want width? The 4231 has wingers. You want to really control possession? The 4132 keeps things narrow and makes it easier to connect passes.
For Mastroeni, however, it almost seems like the idea is to just see if this formation works better for his guys than last week's. Experimentation is all well and good, but the Rapids have the look of a team that needs to settle on one formation and get closer to a regular eleven. Their constant rotating and formation swapping have caused them to look disconnected - particularly on transition - and their form has suffered badly.
How badly? The Rapids were 6W-3D-4L after thirteen games, but over their last ten matches they've gone 2W-3D-5L, including three straight losses and four out of five. It's not exactly due to a difficult run of games, either: In this ten-game stretch, Colorado only played a team that currently has over 30 points three times (FC Dallas twice, Real Salt Lake once). They even managed a 3-0 loss to New England, who have lost nine of their last ten games.
Despite all that, the Rapids rotation looks set to continue, making this lineup a tough one to call. In trying to discern any pattern to Mastroeni's choices, I've noticed a tendency to play the 4231 on the road or against good teams. D.C. United isn't a great team at the moment, but we're stronger than the teams Colorado has been playing of late and we're at home, so I'm going with a 4231. Be warned, however, that Colorado's 4231 has sometimes turned fluid enough that it looks more like a 4141 or 4222:
Let's start with the simple stuff first. Clint Irwin will be in goal, and Drew Moor will be partnered by Marvell Wynne at center back. Wynne isn't really a good fit there, but as you may have read in Behind Enemy Lines, none of the natural center backs has stepped up in the wake of Shane O'Neill's baffling knee injury. Ahead of them will be Jose Mari, who Mastroeni has started whenever he's fit. The Spaniard has proven to be a bit injury prone, but was unscathed in Colorado's 3-1 loss at FC Dallas last week.
Wynne's move to central defense has also disrupted things for the outside backs, where he was doing alright in his natural right back role. Chris Klute - last year a terror down the left side - has spent as much time on the right as on the left, which has meant starts for Marc Burch. However, Burch is only narrowly preferred over Thomas Piermayr, whose inclusion would let Klute play left back. The safe way to think of this is that Klute will be on one side, and either Burch or Piermayr will be on the other.
So we've established that Irwin, Wynne, Moor, and Jose Mari are highly likely to start in specific positions, but there are more reliable starters that have less well-defined positions. Klute is joined by Nick LaBrocca, Vicente Sanchez, and Dillon Powers. Thankfully, the 4231 reduces the variables with this group (though Powers has played where LaBrocca is pictured, and Sanchez has played the #10 role).
If I felt the Rapids were more likely to play with two strikers, Sanchez would be the withdrawn forward. LaBrocca would play to the right if Mastroeni chose the 4312, but in the 4132 has often lined up in the middle with Powers out on the left. That's not a good use of Powers, who is something of a throwback as a playmaker, but it probably doesn't concern us. Expect to see him in the middle looking to switch the point of attack on a regular basis.
The last two times Colorado has played a 4231, they've chosen Carlos Alvarez as their left winger. Alvarez is very much an inverted player out there, as his natural role is probably where LaBrocca will end up in this alignment. He does do well to get into shooting positions, but otherwise looks a bit uncomfortable out there. Dillon Serna is an exciting young player who could play wide left, but Mastroeni seems to only give him starts when they play the diamond midfield.
Up top, Deshorn Brown is among the best eleven players for the Rapids, but his game doesn't mesh all that well with how the Rapids play in this formation. They want to be a possession team that plays fairly attractive soccer, but they sorely need a hold-up presence. Brown is a vertical threat due to his speed, but he's not going to contribute much if the Rapids find him with his back to goal. There's always a chance that Edson Buddle gets a start for just that reason, even if his form at 33 is not particularly impressive. Buddle is the tactical fit the Rapids need, and Mastroeni hasn't been afraid to bench his top youngsters.
Still, Brown is more likely, and his presence means United's midfield pressure needs to be excellent. The Rapids tend to play a lot of harmless possession, but any team in MLS can turn a guy like Brown into a threat running in behind if they have time to spot his run. The Black-and-Red have played a higher-than-expected line against speedy teams in the past, but it only works if the midfield makes forward passing difficult.
Another significant worry is Sanchez running at Taylor Kemp. At 34 and about 145 lbs, Sanchez isn't going to trouble Kemp for speed or strength. Instead, the Uruguayan is a big problem due to his soccer brain. Sanchez has a knack for getting 1v1 - aided in no small part by how often Powers looks to swing the ball out to him - and causing issues in and around the box. The Rapids win a lot of PKs, and between Brown and Sanchez it's not really a surprise as to why. Kemp is going to have to improve on his positioning and his anticipation as compared to even his better spells in Houston, or we can expect a steady diet of Sanchez running at him.
Going forward, there are times where Moor looks like he's doing it all by himself. The formation changing has left spacing issues all over the field, and teams like that always struggle in transition. On top of that, Wynne's decision-making is problematic around the box, and both Nick DeLeon and (especially) Sean Franklin can beat Burch down the flank for speed. Last year's threat of Klute surging forward to notch an assist has been reduced, as Mastroeni uses his outside backs to support possession rather than create penetration.
When United has the chance to play quickly, the idea should be to play away from LaBrocca, who covers the most ground for Colorado's midfield defensively. Jose Mari plays an anchor role, so he'll have a long distance to cover if he decides to shut the play down upfield rather than stay home and wait it out. On fast-moving plays, the Rapids are usually a step behind in terms of anticipation, which is a great thing for guys like Fabian Espindola and Chris Rolfe.
Starting the game well could help make this one an easier match. In the first 14 minutes of their last three matches, the Rapids have coughed up four goals. That link goes on about shot totals and possession after it makes that point, but there's a reason for that: Colorado falls behind early, giving teams the luxury of playing a counterattacking game.
Last week, FC Dallas was outshot 24-7, and they ceded 61% of possession at home, but they still controlled how the game was played and were richly deserving of their win. In this grueling stretch of games, United would really do well to go full throttle for the first 30 minutes to take a lead and then let the Rapids do all the huffing and puffing. Colorado's lack of cohesion and their struggle for confidence make them an easy mark at the start of games right now.
On set pieces, the Rapids don't defend particularly well. They're not a particularly small team, and Irwin doesn't have unusual problems when it comes to claiming crosses. Instead, it's a simple focus issue. The Rapids are tentative on the initial service, and on plays where they've only half-cleared the ball they're bordering on disaster if the ball is sent back in. Last week, Dallas hit them for an opener that summed it all up. Ball-watching is a sin, and the Rapids right now are on their way to Hell.
At the other end, Moor is an elite target and has been for years. However, he's pretty much the entire threat unless you count the long-range shooting of Jose Mari and Powers on half-clearances. Still, Sanchez and Powers are both decent corner kick takers, and decent delivery means you can be a threat without having a team of angry giants to aim at. Powers is also good on long distance services, while Burch is the main threat to go to goal. Advice to the wall if Burch is standing over the kick: Don't jump! Let the ball hit your shins. If you jump, the myth that Burch is a free kick wizard will never die.
Overall, United should enter this game as the favorite even with Eddie Johnson suspended and left back a major source of concern. The Rapids have a lot of good pieces, but as a team they aren't where they should be at this point in the season in terms of playing as a unit. Throw in their recent defensive vulnerabilities - particularly on the road - and a team-wide loss of confidence, and you have an opponent coming to RFK with more problems than United has at the moment.
If United can play at a high tempo early, the odds are that some quality chances to take the lead will present themselves. Even if the Rapids are sturdy at the start, the return of Perry Kitchen should help the Black-and-Red stay ferocious in the midfield, reducing the threat of the Colorado possession game. Eventually, their creaky defense should crack. This game isn't a must-win by any means, but it would be a disappointing fixture to lose.