SEATTLE – FC Dallas are in the midst of a potentially historic MLS campaign that has already seen them win the US Open Cupand the Supporters’ Shield.

But those hopes are on the ropes following Sunday night’s 3-0 blowout defeat to the Seattle Sounders in their Western Conference semifinal opener at CenturyLink Field.

The loss left Dallas head coach Oscar Pareja trying to explain exactly what led to an exceedingly out-of-character second-half meltdown in which his club conceded all three goals in eight minutes.

“In the second half, in the first 20 minutes, Seattle outplayed us. We have to accept that,” Paerja said after the game. “Tonight we played against a very good team. That first 20 minutes they were very sharp. We allowed them to get in those spaces and score those goals.

“We have to accept that they were much, much better, especially during that part of the game.”

Pareja said he was more or less pleased with how his side played in the first half of Sunday’s contest, which was a scoreless deadlock at halftime.

But even in a defensive 5-3-2 formation, FCD’s backline unraveled almost immediately following the second-half kickoff, conceding the opener to Sounders forward Nelson Valdez in the 50th minute before Nicolas Lodeiro put the game – and maybe the series – away with two more goalsbefore the 60th minute.

“The first goal took us by surprise because we had the game controlled and we didn’t expect for the game to be unbalanced with that play,” Pareja said. “We had center backs in the box and after the cross, we were neutralizing that in the first half so I didn’t see anything in those plays.

“But after that goal, I thought we could be more mature and have more composure on the field and not let them score the second one. In that part, we should have been much better.”

With his club’s backs against the wall, Pareja said his objective is to try and maintain an optimistic outlook going into the second leg of the series. He took care to note that FCD has overcome many obstacles already in a season where star winger Fabian Castillo departed for Turkey and playmaker Mauro Diaz was lost to a torn Achilles.

“I have to keep the optimism for the group that has overcome [adversity] during the year,” Pareja said. “We’ll keep fighting.

“I think this team has shown during the year that we can overcome difficult situations. Why not this one, as well?”