WASHINGTON — The entire season-opening three-game series between the Washington Nationals and New York Mets was called off on Friday because of a COVID-19 outbreak on the 2019 World Series champions, who had four players test positive and another five quarantining after contact tracing.

The Nationals announced the postponement of games scheduled for Saturday and Sunday at their stadium. That news came a day after Thursday night’s opener was scratched just hours before it was supposed to begin with Max Scherzer pitching for the Nationals against Jacob deGrom of the Mets in a matchup between the recipients of a combined five Cy Young Awards.

“We’re in crisis management mode,” Washington general manager Mike Rizzo said in a video call with reporters Friday.

More than a third of the 26-man roster submitted for opening day is affected by the outbreak and wouldn’t be able to play at this point. Rizzo said players who didn’t make the team will get called up from the Nationals’ training site in Fredericksburg, Virginia.

“Our depth is going to have to shine,” the GM said.

A total of four players have tested positive for the illness caused by the novel coronavirus – including one Rizzo said Thursday was considered merely a “likely positive” – and another five are under quarantine after contact tracing determined they potentially could have been exposed, too. A staff member is also in quarantine.

Rizzo has not identified any of the players involved – and said he will not.

The Nationals did not report a single positive COVID-19 test throughout their six-week spring training camp that ended at the start of this week. The team flew from Florida to Washington on Monday; the first positive of the current outbreak came from testing that day.

“A virus is a virus. It’s very contagious. So I think it could happen in many, many different ways. I don’t think it’s a breach of protocol or inadequate protocols,” Rizzo said. “But it’s something that happened. We’re going to try to find out how it happened and investigate it and see if we can stop it from happening again.”

Major League Baseball and the players’ union issued a testing update Friday, saying there were four new positive tests – three players and one staff member – from the 14,354 tests administered over the past week across all of the sport, a 0.03% rate.

One of Washington’s players had a fever, according to Rizzo, but others involved were not showing symptoms.

“The player with the fever is doing fine. He’s feeling much better. Close to normal,” he said. “And the other players feel fine.”

Washington’s next scheduled game would be Monday at Nationals Park against the NL East rival Atlanta Braves, and Rizzo said he expects Scherzer to start.

“We are planning to play Monday,” Rizzo said. “That’s our plan. Although this is a day-by-day thing.”

He wants the players who aren’t being isolated to be able to work out at Nationals Park before competing, perhaps as soon as Saturday, if MLB allows.

“You can’t just go from a dead stop in this postponement to ramping up to play the Atlanta Braves and not expect (there) to be injuries,” Rizzo said.

“But these other players, it’s just hard to have them sitting and playing video games or whatever for two or three days and then to ramp up again. To me, it’s a safety issue and we’ve got to get these guys’ blood flowing,” he said. “We’ve got to get them moving around so they don’t go into the season going from zero to 100 miles an hour without preparation for the last couple of days.”