WASHINGTON -- Houston Dynamo presently reside in first place in the Western Conference and also own the overall points lead in Major League Soccer, achievements that were reflected by the selection or involvement of six Dynamo players in the MLS All-Star Squad, coached by Dynamo boss Dominic Kinnear.Meanwhile, D.C. United sit four points back of Houston, are in hot pursuit of the top spot in the East, remain active in CONCACAF international competition -- and not a single member of Tom Soehn's squad earned an All-Star nod of any sort.So when United visit Houston this weekend for a matchup with the league-leading Orange, kicking off an arduous 72-hour period that could prove to be a defining span in United's season, there are any number of reasons why it will be no ordinary league match for the Black-and-Red."It's a huge game," said D.C.'s Santino Quaranta, fresh off a Gold Cup stint with the U.S. national team. "Being on the road -- and they're a good team, Houston's a good team -- I think it's one of those games where it really is a test of your character, overall, for everybody here. You see where you stand as a team after this game."Dynamo tend to dominate at Robertson Stadium -- they've lost just two league matches over the past year and a half -- and this time of year finds the Bayou City at its most inhospitable, with suffocating humidity levels and temperatures routinely hovering around 100 degrees. D.C. will also have limited recovery time afterwards: Tuesday's CONCACAF Champions League match against CD Luis Angel Firpo will necessitate flying directly from Houston to El Salvador for an even more pivotal contest.Then there's the matter of the All-Star snub. Thanks to Champions League qualifying, D.C, New York and Toronto knew months ago that no one from their teams would be able to participate in Wednesday's marquee event in Utah and Kinnear had to choose his squad accordingly. But the lack of representation on the 32-man official list nonetheless rankles many on East Capitol Street."Dom had nothing to do with that. Obviously, he couldn't pick from three teams," said Soehn on Friday. "[But] I think it's a motivation for our guys to be looked over, regardless of their playing in the game but at least being selected to the 32 (including alternates). For me, it's shocking to see that none of our guys were there. It's almost disrespectful. I know I wasn't happy about it, so I can imagine their feelings on it. They were slighted and it was wrong, for sure."United have yet to win or even score in four previous trips to Houston. But one veteran of those difficult occasions believes that a breakthrough might be close at hand."We've always had good games there, but they've always just seemed to be a little bit on top when the final whistle blows," recalled right back Bryan Namoff. "We need to go in there with the same mentality we've gone with in the past, but this time we want to be on the other end, on that winning side. In order to do that, we need a good, collective team performance."United are eager for a boost after frustrating breakdowns in their last two matches (San Jose and Firpo) led to draws when D.C. badly wanted -- and needed -- victories instead. Quaranta's return is welcome news on that front and he hopes to help his teammates rediscover their "swagger," starting at Robertson Stadium."Everybody understands that it takes a lot of hard work: you have to put together a 90-minute performance," said Quaranta. "We've been talking about that for a long time and hopefully -- win or lose -- we can just put in a good performance, all 11 guys on the field. That's what we're looking to do this weekend."Charles Boehm is a contributor to MLSnet.com.