The Vancouver Whitecaps are expected to be short-handed for Sunday’s night’s MLS showdown with rival Seattle with nine players away for international duty.

What the Western Conference-leading Whitecaps (9-1-5, 32 points) didn’t expect was half of their traveling party coming down with a gastrointestinal illness on their way back from a 5-0 loss last weekend to Cruz Azul in the CONCACAF Champions Cup final.

That caused the Whitecaps to miss a day of training and led to questions of whether Sunday’s match might be postponed if host Vancouver didn’t have enough players to field a team.

“I don’t really know,” Whitecaps coach Jesper Sorensen said when asked how many players he expected to have available. “We had some guys coming out on the pitch (Friday) who have been ill, and they left early, so we don’t really know where they are and then we have some guys not even returned yet.”

Whitecaps CEO and sporting director Axel Schuster tried to remain philosophical.

“Maybe it’s better to have all negatives in one week this year,” Schuster said of the Champions Cup loss and illnesses. “The game, there was a lot of frustration and a lot of sadness. It was a special situation because a lot of starters left the team, and it probably helped to distract from what happened on (June 1).”

Even without captain Ryan Gauld (knee), the Whitecaps are on a franchise record-tying 10-game unbeaten run (5-0-5) in league play.

The Sounders (7-5-5, 26 points), are coming off an uncharacteristic 3-2 loss last weekend to Minnesota United, allowing three goals in a seven-minute span early in the second half to suffer the first home defeat of the season and their first all-time to the Loons at Lumen Field.

Sounders coach Brian Schmetzer said the Whitecaps’ woes won’t affect his team.

“We’re going to control the controllables,” Schmetzer said. “I can’t control who Jesper is gonna put on the field, but I can control who I put on a field and making sure that they’re ready.

“That’s going to be a dangerous team because they have a built-in excuse. I know they’re gonna play hard, whoever steps on the field.”

The Sounders had hoped to have Jordan Morris, the franchise’s all-time leading goal scorer, back for the match from a hamstring injury, but Schmetzer said Morris suffered a setback in training and would be unavailable.

–Field Level Media