The Washington Spirit’s game against the Portland Thorns on Saturday night in Oregon was postponed because of positive coronavirus tests among the Spirit, the National Women’s Soccer League announced.

Four members of the Spirit tested positive, the NWSL said. Details regarding when the match will be rescheduled will be announced in the coming days, the league said.

“I personally apologize to our fans,” Portland Thorns owner Merritt Paulson said in a tweet Saturday. “We expected one of the biggest Thorns crowds of the season tonight. Hopefully we are cleared to play [Tuesday]. Frustration level is very high given the facts as I understand them. Will work [with] the NWSL to sort this/prevent similar issues.”

Paulson later tweeted that the game would not be played Tuesday.

The Spirit has multiple unvaccinated players, according to a person familiar with the situation. A Spirit spokeswoman declined to comment beyond the league’s news release. Washington’s next scheduled game is against OL Reign on Sept. 12 at Audi Field.

A player who tests positive for the coronavirus must isolate for 10 days and be symptom-free for at least a week before returning to physical activity, per the NWSL’s medical protocols. Team members exposed to others who test positive also must follow the protocols before returning.

The postponement came as the Spirit is consumed with off-field controversy. The club is in the midst of a struggle for control between co-owners Y. Michele Kang and CEO Steve Baldwin. Last month, Richie Burke stepped down as coach, was reassigned to the front office and was suspended when the team opened an investigation after The Washington Post detailed allegations by former players of verbal and emotional abuse by Burke. Baldwin and the Spirit’s president of sporting operations, Larry Best, were involved in hiring Burke in 2018 after he had been accused of abusive behavior toward young players while coaching a Loudoun County travel team.

On the field, the Spirit, led by interim coach Kris Ward, has slipped, too. Washington is 1-2-2 in its past five games. During its previous match Aug. 29 — a scoreless draw with the North Carolina Courage — Spirit fans called for Baldwin to resign.

Washington (6-5-5, 23 points) entered Saturday sixth in the NWSL with about two months remaining. Six teams qualify for the playoffs.

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Molly Hensley-Clancy contributed to this report