Less than two weeks after winning its first championship, the Washington Spirit on Wednesday confronted the uncomfortable realities of the National Women’s Soccer League’s growth — and an impending expansion draft — by trading Tegan McGrady to the San Diego Wave.

The Spirit would have preferred to retain the left back, but with San Diego and Los Angeles-based Angel City FC joining the league next season, Washington was in danger of losing two players in the Dec. 16 draft.

With this preemptive move — which also included Washington giving up a low 2022 first-round draft pick and an international roster slot — the Spirit received immunity from San Diego selecting one of its unprotected players. That means the reigning champions will lose no more than one player, to Angel City, in the nine-round draft.

It also allows Washington to protect another young player, such as rookie forward Tara McKeown. Teams are allowed to protect only nine of about 25 players. Kansas City is exempt from the expansion draft because of a deal it made with the league when it took over the Utah franchise last year.

“Ahead of the expansion draft, we faced the challenge of finding ways to position the club for sustained success by keeping as much of our core as possible. This trade aligns with that focus,” team president Ben Olsen said in a statement. “We are very grateful to Tegan for her contributions.”

McGrady, a Stanford graduate and former U.S. youth national team defender, was the seventh pick in the 2019 draft. This year she appeared in 16 of 27 matches and started 11, including all three postseason games. Julia Roddar and Kelley O’Hara, the starting right back, also played on the left side this season.

In San Diego, McGrady, 24, will join a back line that includes U.S. World Cup central defender Abby Dahlkemper, who returned stateside in August from England’s Manchester City to play for Houston. The Wave acquired her rights this week.

The expansion draft prompted the North Carolina Courage this week to trade star midfielder Sam Mewis to the Kansas City Current for defender Kiki Pickett and a 2022 first-round pick. That deal allows the Courage to protect its other allocated U.S. national team player, forward Lynn Williams. (Teams are allowed to protect only one.)

The Spirit has three allocations: O’Hara, captain Andi Sullivan and defender Emily Sonnett. Should Washington protect Sullivan, it would hold its breath on Angel City’s decisions.

San Diego and Angel City are allowed to claim one U.S. allocated player apiece. Candidates might include Chicago’s Julie Ertz and Alyssa Naeher.

Several additional trades are expected around the league before Friday’s deadline. The trade window will reopen before the college draft Dec. 18.

Note: The Spirit is in preliminary discussions with interim coach Kris Ward about becoming the permanent boss, people close to the talks said. Aside from the team’s two forfeits for pandemic protocol violations, Ward was undefeated (9-0-3) after he replaced Richie Burke in mid-August.