Crystal Dunn, left, was the NWSL MVP in 2015 and a two-goal scorer in the 2016 championship match. (Katherine Frey/The Washington Post)

Crystal Dunn, a rising star with the top-ranked U.S. women’s national soccer team, has left the Washington Spirit to sign with English club Chelsea, the second prominent player to depart since the National Women’s Soccer League final three months ago.

She follows captain Ali Krieger, who clashed with the coach and owner before being traded to the Orlando Pride in November.

Dunn, a dynamic attacker who won the 2015 league MVP trophy, was free to pursue other opportunities after the expiration of her contract with the U.S. Soccer Federation, which underwrites the NWSL and allocates national team members to the 10 teams. Krieger and Dunn were the Spirit’s only U.S. team representatives.

They were among a group of players who had grown disenchanted with the Spirit organization, several sources said. Dunn played down her issues with the Spirit, saying in a phone interview from Europe: “My decision is based on trying a new environment. I absolutely loved the Spirit. It was a hard decision, but it’s the right time for me.”

Dunn, 24, is the second prominent national team figure to move overseas this winter: Forward Alex Morgan signed a six-month pact with French club Olympique Lyonnais, the reigning European champion.

While Morgan plans to report back to Orlando this summer, Dunn has no such arrangement, even though the English season ends in May, the second month on the NWSL calendar. Her contract does include options to leave if things don’t work out, but she said, “I will not be in the NWSL in 2017.”

Crystal Dunn (Courtesy of Chelsea FC)

Dunn was in London about a month ago, touring Chelsea’s facilities and meeting club officials.

“I felt at home,” she said. “After the visit, we had some conversations. What’s it going to take? They knew I was interested, so it was only a matter of dotting some I’s and crossing some T’s.”

Contract terms were not disclosed. She is the first high-profile American to sign a major deal with a team in the English league, which is a step below the NWSL but, with increased backing from traditional clubs such as Chelsea, is beginning to grow.

Dunn’s departure is a setback for both the Spirit and NWSL, which is seeking to gain a lasting foothold after the failure of two previous women’s pro soccer ventures (WUSA and WPS).

“Of course it hurts to lose such a talented player,” Spirit Coach Jim Gabarra said, “but this is professional sports, and every time there’s a roster spot open, it creates opportunities for others.”

After a U.S. camp in the Los Angeles area this month, Dunn will join Chelsea full time in late January. She’ll return home regularly for national team events.

Before signing with Chelsea, she consulted with U.S. Coach Jill Ellis.

“I told her I want to do it but also am very committed to the national team,” said Dunn, a winger whose 14 U.S. goals in 2016 were third on the squad behind Morgan and World Cup hero Carli Lloyd. “Jill told me, if I was going to do it any year, it’s this year. It was a good feeling having her support. That was something very important to me, being able to feel as though I am part of the national team and not feel as though I am missing out on opportunities.

“It’s a great deal, being able to do the national team and also have the experience of playing overseas.”

Chelsea is a founding member of the 19-team FA Women’s Super League, which features two divisions and promotion-relegation. Home matches are played at a 3,000-seat suburban stadium. The Blues won the top-flight title in 2015 and qualified for the UEFA Women’s Champions League the past two years.

Dunn is not the only American eyeing England: Multiple sources said Heather O’Reilly, who retired from the national team last fall, has spoken with London-based Arsenal. The winger, 32, played the past two seasons in Kansas City after two in Boston.

Every member of the 2015 U.S. World Cup squad and 2016 Olympic team was domestically based. And over the years, the few aligned with European clubs, such as Krieger (Germany) and Lindsey Horan (France), have moved to the NWSL. However, with big European clubs beginning to invest more heavily in women’s soccer, U.S. players have greater club options abroad today.

Meanwhile, the national team players have been locked in a long-running labor dispute with the USSF. The collective bargaining agreement expired Dec. 31, and, while negotiations continue, the previous terms have carried over.

The USSF compensates about two-dozen elite players for service with both an NWSL squad and the national team. Because Dunn will collect a salary from Chelsea, she’ll accept a prorated deal for national team activity.

By joining the English team, she leaves what sources say was a toxic atmosphere in Washington last season.

Krieger, a Northern Virginia native who joined the team for the inaugural 2013 season, was unhappy with Gabarra’s playing style and player management. She differed with owner Bill Lynch, a local software executive, on how he ran the team. Those sources, ranging from players to people familiar with the team, also cited communication issues between Gabarra and the players.

One source, who requested anonymity in fear of retaliation, said the players “went to the championship, and yet were so unhappy.”

Krieger did not respond to interview requests. A day after she was traded, the defender, 32, told her half-million Instagram followers that the deal was a “surprise” but “I do think change can be a good thing.” She learned of the trade from Orlando officials, not Washington’s.

Despite the successful season, several others are gone or possibly on the way out.

Shortly after the season ended, Argentine forward Estefania Banini, Washington’s leading scorer and a free agent, signed with Spanish club Valencia.

Annapolis native Christine Nairn, a starting midfielder coming off a quality season, was traded this past fall to her previous team, the Seattle Reign, for a player and three draft picks. Defender Megan Oyster (15 starts) was dealt to Boston for two players. The latter deal also yielded the No. 1 position in the NWSL’s distribution ranking order, the mechanism for placing unaffiliated U.S. and Canadian national team players.

The status of midfielder Diana Matheson and goalkeeper Stephanie Labbe, Olympic bronze medalists with Canada last summer, is unclear. Matheson, 32, has been with the team since 2013. Labbe lost the starting job the second half of the season.

Dunn said, “I would be lying if Kriegs leaving and Christine Nairn leaving isn’t something I thought about, but my decision to leave was far beyond the different changes happening with the Spirit.”

Addressing fans angered by the trades, Gabarra said: “There are numerous factors and decisions to be made, often based on dozens of moving parts involving multiple points of interest. In most every case, the public will never see or know all of the reasons.”

Gabarra, who is also the general manager, was in his first year with the Spirit after coaching Washington teams in previous women’s pro leagues.

“Reaching the NWSL championship match in Houston was great,” he said. “However, it’s still my job to look forward and continue to put things in place that give the club the best chance to keep reaching for our goals. As is the case with every team in pro sports, changes must be made because no matter how successful a season, things can always be better.”

Lynch made headlines late in the season when he broke league protocol and ordered “The Star-Spangled Banner” played while Washington and Seattle players were in the locker room, preventing Reign star Megan Rapinoe from kneeling during the anthem.

In subsequent days, the players expressed disappointment by posting a statement on the team’s website. Lynch made an emotional, in-person apology to the group for overshadowing the game, a victory that clinched home-field advantage in the playoffs.

The offseason upheaval comes in the wake of the best season in the team’s short history: Washington (12-5-3) was second in the regular season behind the Portland Thorns and defeated the Chicago Red Stars in the semifinals for its first playoff victory.

The team thrived despite Dunn’s lower production. After posting a league-leading 15 goals in 2015, the Long Island native split time between club and country this past year and did not score for the Spirit until late in the campaign. She shined in the final against the Western New York Flash, scoring twice, including a go-ahead strike in extra time, but the Spirit conceded a late equalizer and ultimately lost in a penalty-kick tiebreaker.

“I had in my mind even before the season ended that I wanted to play in Europe,” Dunn said. “It’s just the time in my career to take that option.”