Biggest questions for remaining MLS teams following first legs

Will Kei Kamara show up?

The Eastern Conference semifinal is a battle of the center-forwards. Columbus Crew's Kei Kamara and Montreal Impact's Didier Drogba are the unquestioned offensive leaders for each club. But neither had a particularly good game at the Stade Saputo in Montreal.

Yes, Drogba almost singlehandedly had the Crew's center-backs sent off with a combination of pure strength and exquisite flopping ability, but he didn't contribute to either of Montreal's goals. The former Chelsea star had a noticeable effect on the game, but just didn't do enough to put the ball in the net.

Meanwhile, Kamara basically was invisible. He had just 30 touches on the ball, the least of any Columbus player that was on the field for the full 90 minutes, and never had a good shot at goal. The Sierra Leone-international was tied for the MLS lead in goals in the regular season, just missing the Golden Boot, but didn't do nearly enough to produce chances or play with his back to the goal, which he does so well.

If Columbus are going to climb back from the very reasonable 2-1 deficit in the second leg, it's Kamara, along with Ethan Finlay, that has to step up.

How much will injuries effect the Sounders?

The Seattle Sounders managed to squeak out a 2-1 home win against FC Dallas in the first leg thanks to a late Clint Dempsey free-kick. They did this despite being without two of their most crucial players: Osvaldo Alonso and Brad Evans.

Alonso, who was out of the knockout match with the LA Galaxy and their most recent win over Dallas, is absolutely pivotal to Seattle's central midfield. He provides organization along with superb passing out of the back. While it didn't ultimately impact the result of the contest, the Rave Green certainly felt the effects of his absence.

Evans was replaced by Oniel Fisher at left-back against FCD. He played relatively well against the weaker right side of the visitors (mostly because Fabian Castillo is on the other end of the field) but Evans is talented enough to completely shut down Michael Barrios, as well as neutralizing the passing opportunities for Mauro Diaz.

They both seem likely to play Sunday, meaning both the offense and defense of the Sounders will considerably improve. Now we'll see if they can play well away from the confines of Century Link Field.

Can DC United come back against the Red Bulls?

DC United were very, very bad at home at the New York Red Bulls to start the semifinal round on Sunday. They didn't manage a single shot on target, lost out in the possession battle and were thoroughly overwhelmed in central midfield.

They needed Bill Hamid to keep them in the game. If not, they would have lost by more than 1-0.

Dax McCarty was the goalscorer for New York, and it surprisingly came off a set piece considering the visitors' dominance. It easily could have finished scoreless if McCarty wasn't able to break away from the defense.

Chris Pontius, Davy Arnaud and Bobby Boswell were each out of the starting XI for various reasons, which was surely a factor in the loss considering that two of the three above started in last week's knockout round encounter with New England.

Being on the road for Sunday's second-leg doesn't bode well for DC, but it does give them a chance to equalize the aggregate score on away goals. Beating the Supporter's Shield winners is a tough challenge, so United will have to be on their A-game, something that has alluded them recently.

Who will step up between Portland and Vancouver?

The Portland Timbers and Vancouver Whitecaps played to a dull 0-0 draw in noisy Portland to kick off the Western Conference portion of the semifinals. Neither team seemed to want to get out on the front foot, leaving goalkeepers David Ousted and Jake Gleeson with nothing to do.

"Caution was the order of the day," is how mlssoccer.com's Dan Itel put it in his match recap. This is an accurate description of a game that should have been a little more exciting, with the young talent the teams have. Granted, it's not like those stars didn't have good games, it is just that nobody could mount any significant chances to put the ball in the back of the net.

Portland's Darlington Nagbe, Diego Valeri, Fanendo Adi, Rodney Wallace and Lucas Melano all have the ability to change the game, while the Whitecaps' Kekuta Manneh, Pedro Morales, Octavio Rivero and Gershon Koffie can provide goals in abundance.

After a match in which both sides seemed to be unwilling to attack, the second leg should reveal a player in particular that leads his team to the next round.