Previewing every MLS semifinal match

DC United vs. New York Red Bulls

Nobody expected DC United to make it this far after they stumbled into the knockout round against the Revolution. But here they are ready to face the New York Red Bulls yet again in the Eastern Conference semifinals.

These clubs always seem to find a way to make things interesting. 2012's showdown was one of the best ever, and last year's battle provided some heart-stopping heroics as well. That means this match is must-see TV, if their previous encounters were any indication.

United have been subpar on the road this season, going 1-6-2 since June away from RFK. The good news for them is that they are at home for Sunday's match. The bad news is that if the Red Bulls can pick up an away goal or two, as they did in DC back in April, then they could be golden for the second leg in Harrison, New Jersey.

The Supporter's Shield winners are the clear favorites for this match, but you never know with DC. They might just find a way into the MLS Cup.

Columbus Crew vs. Montreal Impact

This is a very intriguing game.

One team is led by a combination of players like Kei Kamara, Federico Higuain and Ethan Finlay, while the other uses its star-studded offense–which includes world superstar Didier Drogba–to score, score and score some more.

Ignacio Piatti, the Argentinean attacker who has proved to be the perfect compliment to one of the best hold-up strikers of all-time, had a goal and an assist in Thursday's shellacking of Toronto FC. His constant runs at the defense helped him and others slice up Toronto's backline, resulting in three goals for the home side.

Meanwhile, the Crew are coming off a 5-0 creaming of DC United back on decision day (feels so long ago, doesn't it?). They crossed the ball over and over again in order to keep Bill Hamid awake, and Harrison Afful wrecked havoc down the wing when overlapping. Piatti will be forced to defend him, leaving the offense lacking.

Goals will be the story in this one, but don't forget about the defenses. Both have improved as of late.

Portland Timbers vs. Vancouver Whitecaps

The Timbers are coming off a thrilling win on penalties last week, which means one of two things: They are worn out and won't be 100% for their semifinal match against Vancouver; or they use the momentum of a hard-fought victory against a good team to get hot and win their next game.

Whether they are tired or not, Diego Valeri and Darlington Nagbe lead a Portland team that will out-pace any opponent. But Whitecaps' center-back Kendall Waston has been magnificent this season, so of all people, he would have the best chance to out-duel them.

As for Vancouver, they are a high-pressing team that will punish any mistakes, particularly in the midfield. If the Timbers' physical backline protecter, Diego Chara, can't go due to the same injury that kept him out against SKC, the hosts will have an easier time winning the ball in good positions.

In order to grab the advantage heading into the second-leg, Portland can't let them do that.

Seattle Sounders vs. FC Dallas

Both of these teams are in-form, not something you can say about the other games. That makes this a star-studded, marquee matchup. Talent young and old will be on display, with the usual duo of Clint Dempsey and Obafemi Martins leading Seattle while Mauro Diaz and Fabian Castillo, both under the age of 25, will head the attack force of FC Dallas.

Diaz is especially key to this one. He is great off the dribble, shredding the central midfield of many MLS teams in the past, while also acting as the main playmaker for Castillo. But if Ozzie Alonso, the Sounders' midfield stalwart, is fit for the match, he may not have the success he is used to.

The Sounders have serious health problems. Nelson Valdez isn't 100%, Alonso is questionable, both left-backs, Leo Gonzalez and Oniel Fisher, have the injury bug, Brad Evans, their best defender, was hurt against the LA Galaxy and Marco Pappa was out for a lot of the year.

That means the ObaDeuce combo will have to be on full force in order for the Sounders to win.