There are different theories on whether it means very much to have momentum going into the MLS Cup playoffs, but at least in the Union's case we're about to find out.

That's because when the Union open the first of a two-game, aggregate-goal Eastern Conference semifinal series on Sunday at PPL Park in Chester against the Houston Dynamo, the two teams are coming from different directions.

The Union had played well in the final weeks of the season, but then were not at the top of their game in their final two regular-season matches. Houston, meanwhile, finished 4-0-2 to secure second place in the East with 49 points, one more than the third-place Union.

"I'm not saying it doesn't matter," Houston coach Dominic Kinnear said about entering the playoffs on a hot streak.

Yet Kinnear doesn't believe his team gets any edge for the impressive finish. He thinks it is a good feeling to be playing well, but more important that the Dynamo will benefit from a late-season schedule that felt like mini-playoff games.

"Those last five or six games, our team has been under a lot of pressure in those games," he said.

Teams need some breaks, and Houston got one in the regular-season finale, a 3-1 win over the Los Angeles Galaxy. Los Angeles, which clinched the league's best regular-season record, rested all but two of its regulars.

The Union seemed to tense up as they neared a playoff berth. Following a 3-0-4 stretch, the Union clinched a playoff spot in the second-to-last game of the season with a 1-1 tie against a Toronto FC team they had beaten, 6-2, earlier this year. Granted, it was an improved Toronto team, but team manager Peter Nowak suggested afterward that the Union may have felt the pressure of clinching a playoff spot.

Then the Union ended the regular season with a 1-0 loss at the New York Red Bulls on Oct. 20. The first half, in which they trailed, 1-0, and were outplayed, may have been one of the Union's more uninspired performances of the year.

The Union could have clinched one of the three Eastern Conference berths with a win. Instead, they clinched after the Chicago Fire beat the Columbus Crew on Saturday.

Union defender Danny Califf said that having a playoff berth secured could have been a factor against New York.

"That played a role, but I think we came out with just a lackluster mentality," Califf said. "We were trying to tell ourselves that we were 'in it mentally' and everything like that, but certainly once the first few things didn't go our way, you could tell right away for the most part we didn't want any part of the game."

Califf believes there will be no carryover.

"After our first few training sessions this week, there definitely won't be a worry about what happened in that last game," he said.

Nowak believes the last two games will have zero effect on his team.

"The playoffs are not about worrying who won their last 10 or 20 games, it's going to be who wins this series," Nowak said.

The Union were 7-1-9 at home and players and coaches have talked all week about the energy they will receive from the PPL Park faithful.

To the players, the regular season is now ancient history. And considering what happened the last two games, that's not such a bad mind-set.