Halfway through the conference semifinals in the MLS Cup Playoffs, it seems like we could be set for a few upsets.

Each matchup features a two-legged battle with an aggregate score, which means everyone is still alive after the first set of matches. However, one No. 1 seed is currently facing a two-goal deficit while the other could only draw in the first contest.

If these teams do not come back with strong performances in the second leg, fans could be in for a surprise this postseason.

Here is a look at what to watch for in each match, with predictions for which teams will battle in the conference finals.

Eastern Conference

After a 2-0 defeat at the hands of New York Red Bulls, D.C. United are in serious trouble. The team with the most points in the Eastern Conference could be headed out of the playoffs in the first round.

Bradley Wright-Phillips continued his campaign as the top scorer in the league this season, putting himself in rare territory, as Paul Carr of ESPN FC noted:

Meanwhile, the two goals in the first match were set up by the legendary Thierry Henry, which impressed Grant Wahl of Sports Illustrated:

However, it is important to note New York had much more success at home this season. While the squad had 38 goals at home in 2014, it only managed 17 on the road. The minus-10 goal differential in road games was the worst of any playoff team.

Watch for D.C. United to come back with some much better defense at RFK Stadium in the return leg as the team keeps the Red Bulls off the scoresheet. Fabian Espindola and Eddie Johnson will then do their part to at least even up the score with goals of their own.

A 2-0 score would send the match into extra time and eventually penalty kicks, and the home team has what it takes to pull out the win.

Prediction: D.C. United wins match 2-0; D.C. United win 2-2 aggregate in penalty kicks

Columbus Crew entered the first matchup extremely confident but put up a dud against the New England Revolution, losing 4-2 at home.

Crew head coach Gregg Berhalter was especially disappointed in the effort on display, via Andrew King of MLSSoccer.com:

We talked a good game this week, and we didn't play a good game this weekend, and that's an issue to me. We're talking about who we are and what we do, and to me it's about executing; that's what's most important. The last thing I saw today, especially in the first half, was execution. It was the reverse of that. And that's disappointing to me.

New England did not exactly dominate the match, but while Columbus worked on maintaining possession, the Revolution were aggressive around the net and took advantage of opportunities.

Charlie Davies came through with a brace, while Lee Nguyen continued to show why he is one of the most underrated players in the league.

In the second match, Columbus will need to either outscore its opponent by three goals or score at least four of its own with a two-goal differential. This simply does not seem likely after what we saw in the first match.

Look for the home squad to stay conservative to keep it low scoring and eventually leave with a win.

Prediction: Columbus Crew win match 1-0; New England Revolution win aggregate 4-3

Western Conference

While FC Dallas were able to keep things even against the Seattle Sounders, advancing to the next round will not be easy. In fact, allowing a 1-1 draw gives the club surprisingly little chance of winning the matchup.

Going into the second leg, Seattle will need to earn any win or even just a scoreless draw in order to advance. Considering how good the squad is at home, you can almost assume this will come true on Monday.

The Sounders won 12 of their 17 matches at home this year, while FC Dallas earned only four victories on the road all season. A lot of this is thanks to the fan base that keeps showing up in bunches, as Don Ruiz of The News Tribune noted:

You can imagine the CenturyLink Field crowd will be as filled up as it is for a Seahawks game as the fans will their team to victory.

Of course, the elite talent throughout the lineup will also help, as Clint Dempsey looks to make an impact alongside midfielder Osvaldo Alonso. Although the defense can be a bit inconsistent, the team should be able to hold up well enough to earn the win.

Prediction: Seattle Sounders win match 1-0; Seattle Sounders win aggregate 2-1 

As good as the Seattle Sounders have been at home, the Los Angeles Galaxy have been even better with 40 points out of a possible 51, including a plus-30 goal differential. However, this does not mean it is impossible to beat them.

Los Angeles Galaxy might have the big names on the roster like Landon Donovan, Omar Gonzalez, Robbie Keane and others. However, Real Salt Lake did a great job playing like a team to give their opponent everything they could handle in the first match.

Salt Lake took 16 shots, with six of them on net, putting a lot of pressure on goalkeeper Jaime Penedo. While he was able to stop them all to keep the scoreless draw, he might not be as fortunate next time out.

Meanwhile, Andrew Das of The New York Times believes this type of play can continue on the road in the next match:

Javier Morales has done an excellent job of creating opportunities for himself and others all season long, and this should continue in the playoffs.

While the Galaxy could end up scoring themselves, any sort of scoring draw will be enough for Real Salt Lake to advance. Although this is not an easy task on the road, they should be able to pull off the upset in this one.

Prediction: 1-1 draw; Real Salt Lake wins 1-1 in aggregate (away goals rule)

Follow Rob Goldberg on Twitter for the latest breaking news and analysis.

Read more MLS news on BleacherReport.com

Source: Click Here