Jordan Morris strains hamstring as Sounders advance, doubt for U.S. duty

Video via MLS: Sounders' storybook run (1:31)

The Sounders have reached the Western Conference Championship as their upstart run continued with a victory over Dallas. (1:31)

The Seattle Sounders' happiness at moving on in the MLS playoffs on Sunday was undercut by the news that forward Jordan Morris suffered a hamstring strain.

Seattle beat FC Dallas 4-2 on aggregate in the Western Conference semifinals, but Morris came off at halftime of the second leg.

"It is a hamstring strain," Sounders interim coach Brian Schmetzer confirmed after the game. "That is all I can say because we have to get him evaluated. It was a last-minute decision by our trainers upon examination at halftime."

The Sounders' playoff run does not continue for another two weeks because of the international break, though Morris was named to the United States squad to face Mexico and Costa Rica in World Cup qualifiers.

Schmetzer suggested that Morris would not be able to perform at his best for the U.S. this week.

"That is not of my control," he said. "What is obviously the most important thing is the health of the players. I don't think that with the games the national team has coming up they will want to take an injured player, but it is early and he will be evaluated by our staff and the United States training staff as well."

Despite dropping the second leg in Dallas 2-1, the Sounders rode their 3-0 first-leg win to advance.

"We did not have much flow early on and it was pretty much one-way traffic," Schmetzer said. "We were under the gun early and give credit to Oscar [Pareja, FC Dallas head coach] for his game plan. We were able to withstand the pressure that Dallas put on us.

"I think that is what helped us persevere against a team that was going all out trying to press to get back into this series."

Dallas had taken a 1-0 lead at half-time through Tesho Akindele's 25th-minute goal and midfielder Brad Evans admitted the hosts had more chances to chip away at the first-leg deficit.

"They came out and pressed," he said. "We knew the situation and you can prepare as much as you want, but when you come into a place up 3-0, we all knew they were going to throw everything they had at us and they showed why they were able to win two trophies this year. We were lucky to only be down 1-0 at half."

Schmetzer praised his team for making the right adjustments at half-time that allowed Nicolas Lodeiro to find a crucial away goal that supplied Seattle with an insurmountable lead.

"I told the team we need to play a little better in the attacking half of the field," he said. "We needed to connect on our passes better because we were not going to be able to withstand another 45-minute onslaught from Dallas."