The National Women’s Soccer League tournament transpiring in suburban Salt Lake City has taken a physical toll on the Washington Spirit, permanently sidelining captain Andi Sullivan and temporarily derailing, among others, U.S. World Cup midfielder Rose Lavelle.

But as the Challenge Cup enters the knockout stage, the second-seeded Spirit (2-1-1) is poised to get its second wind and make a run to next weekend’s title.

New Jersey-based Sky Blue FC (1-2-1), the No. 7 seed, is the quarterfinal opponent at 12:30 p.m. Saturday in Herriman, Utah. The winner will face No. 3 OL Reign (Tacoma, Wash.) or the No. 6 Chicago Red Stars in Wednesday’s semifinals in nearby Sandy.

Washington is the highest remaining seed after the No. 8 Portland Thorns stunned the No. 1 North Carolina Courage, 1-0, on Friday.

The Spirit will go forth without Sullivan, an emerging figure on the U.S. national team who tore the meniscus in her left knee last weekend and underwent surgery Thursday. The Lorton, Va., native is out three to six months.

Although Lavelle missed the first-round closer against Houston with an ankle injury, Coach Richie Burke said he expects her to play in some capacity Saturday. A final training session Friday was to help determine her match status, Burke said.

Midfielder Jordan DiBiasi is also expected to return after sitting out one match with a hip injury.

Carli Lloyd and Mallory Pugh, Sky Blue’s U.S. stars, withdrew from the tournament before it started because of injuries.

The Spirit played four matches in 16 days after no formal competition in more than eight months, a demanding stretch that stressed the roster.

“It’s a daunting prospect to play another three games in eight days to win this whole thing,” Burke said. “But it’s something that we’ve welcomed. Look, let’s go play. Let’s go and try and be us and try and do our thing.”

Sullivan’s role in deep central midfield — where she sets the tone and pace, disrupts attacks and launches them — will be missed.

“Andi is one of the best leaders I’ve ever been fortunate and lucky enough to play with, and so not having her here, it’s going to be different,” DiBiasi said. “It’s going to be a test for us.”

Although Lavelle fills a different role than Sullivan, greater responsibility will fall on the national team star.

“Every time Rosie sets foot on the field, there’s massive expectations,” Burke said. “She might feel compelled to fill up a void left by Andi, but they are two completely different players. Every time Rosie plays, there’s pressure on her. We don’t think of it that way; we are just ecstatic to have a player of her caliber.”

The youthful Spirit has been emboldened by the first-round results, the first three coming against the top finishers in the 2019 regular season: a defeat against two-time defending champion North Carolina but a victory over Chicago and a draw with Portland.

Although most of the regulars are 25 or younger, the Spirit has performed with poise.

“The players we have added have a confidence about them that is very mature,” veteran defender Tori Huster said. “It’s almost like they aren’t worried about making mistakes. They want to play, and they know mistakes are going to happen, and it’s more so what is going to be our response to those mistakes. Their mind-set is very growth-oriented.”

THORNS 1, COURAGE 0: Winless in the opening round, Portland used rookie Morgan Weaver’s 68th-minute goal and Britt Eckerstrom’s spectacular goalkeeping to stun previously perfect North Carolina.

On Wednesday, the Thorns will face the No. 4 Houston Dash, which defeated the No. 5 Utah Royals in a penalty kick tiebreaker, 3-2, after a 0-0 draw.

Eckerstrom (Germantown, Md.) made several excellent saves before Weaver, the second overall draft pick from Washington State, slipped inside her marker and put away Raquel Rodriguez’s cross from six yards.

Eckerstrom made an extraordinary save on Debinha’s 18-yard free kick in the 79th minute.

Moments later, she thwarted Debinha surging into the penalty area and blocked the rebound bid.