The Washington Nationals fired both manager Dave Martinez and general manager Mike Rizzo on Sunday night in the midst of the latest in a string of disappointing seasons since the 2019 World Series triumph.

The duo led the franchise to its first championship that year but have failed to post a winning record in any season since and, at 37-53, did not look likely to do so this year.

“While we are appreciative of their past successes, the on-field performance has not been where we or our fans expect it to be,” Mark Lerner, the Nationals’ principal owner, said in a statement. “This is a pivotal time for our Club, and we believe a fresh approach and new energy is the best course of action for our team moving forward.”

The Nationals had the option to extend Martinez by another year with a deadline for the decision set for mid-July, according to multiple reports.

The franchise decided to fire him — and Rizzo — midseason rather than decline the 2026 option and allow Martinez to finish the campaign as a lame duck. 

Martinez was the sixth-longest tenured manager in the majors, tied with New York Yankees skipper Aaron Boone. 

The Nationals did not immediately name an interim manager Sunday. That announcement will arrive Monday, the team said in a press release.

Mike DeBartolo, the team’s senior vice president and assistant general manager, will serve as the interim general manager.

He’ll oversee next week’s MLB draft, where the Nationals hold the first overall pick for the first time since 2010, when the team drafted Bryce Harper.

“Mike DeBartolo is a smart and thoughtful executive, and we’re fortunate to have him as part of our organization,” Lerner said.

“As we hold the No. 1 overall pick in this year’s MLB Draft and look ahead to the trade deadline, we are confident in his ability to lead the baseball operations staff through these next, important months,” he said.

DeBartolo joined the Nationals as an intern in 2012 and has worked as an assistant general manager since 2019.

“Nationals fans have a lot to be optimistic about, and we see these changes as a difficult, but necessary move in a positive direction,” Lerner said. “As has been the case since my late father took control of the team almost 20 years ago, our family remains committed to winning and bringing another World Series trophy to Washington, D.C.”

The Boston Red Sox completed a sweep of the Nationals in the District on Sunday, dropping Washington 16 games below .500 for the first time all season.

June was particularly rough.

The Nationals finished the month with a 7-19 record, reaching rock bottom with an 11-game losing streak that culminated with three defeats to the league-worst Colorado Rockies. Prior to that 11-game skid, the Nationals had been playing at just under a .500 pace and were in third place in the National League East versus last place now.

Though he led the Nationals to winning records in his first two seasons in Washington, Martinez could never rekindle the success of 2019. He leaves the franchise with a 500-621 record across eight seasons.

“Davey’s ability to connect with our staff, our players, our fans and our community set him apart,” Lerner said. “While this chapter has come to an end, we know that it doesn’t close the book on what should continue to be a long and successful career in baseball.”

Rizzo joined the Nationals in 2007, just two years after the franchise moved to the District after starting its existence as the Montreal Expos. He began as an assistant general manager before transitioning to general manager in 2009.

In his role, he oversaw a years-long rebuild that turned a cellar-dwelling club into a perennial playoff contender. Rizzo drafted franchise pillars like Stephen Strasburg and Harper before orchestrating key signings like ace Max Scherzer and slugger Jayson Werth.

In recent years, Washington’s team-building priorities shifted. Rizzo publicly said he did not have the funds available to make splashy signings or retain key players. Instead, the front office worked along the margins and flipped stars like Scherzer and Trea Turner for prospects.

“When our family assumed control of the team, nearly 20 years ago, Mike was the first hire we made. Over two decades, he was with us as we went from a fledgling team in a new city to World Series champions,” Lerner said. “He played an instrumental role in leading the transformation of our farm system and building a roster that reached an unprecedented level of organizational success.”

More recently, Rizzo was responsible for the trade that sent Juan Soto to the San Diego Padres in exchange for a crop of prospects that included James Wood, MacKenzie Gore and Robert Hassell III.

Wood and Gore were named All-Stars for the first time in their careers on Sunday.

The Nationals are off on Monday. They return to the field Tuesday for the start of a three-game series in St. Louis against the Cardinals. 

• Liam Griffin can be reached at lgriffin@washingtontimes.com.