The Philadelphia Phillies shut their spring complex after five players tested positive for COVID-19 and at least two others teams closed camps Friday, raising the possibility the coronavirus pandemic could scuttle all attempts at a Major League Baseball season.

The Toronto Blue Jays shuttered their site in Dunedin, Florida — about five miles from the Phillies' camp in Clearwater — after a player showed symptoms consistent with the virus.

The San Francisco Giants' facility in Scottsdale, Arizona, was shut after one person who had been to the site and one family member exhibited symptoms Thursday.

Also, the Houston Astros said a player working out at their spring camp in West Palm Beach, Florida, tested positive several days ago and was recovering.

The closures came while MLB owners and players try to negotiate a deal to begin the season amid the pandemic, with the parties stuck in a bitter dispute over money.

The sides had hoped to have players begin testing Tuesday and then start a second round of spring training by next weekend. Most teams would likely hold those workouts at their home ballparks, rather than at their spring camps in Florida and Arizona.

Earlier this week, Deputy Commissioner Dan Halem wrote in a letter to players’ union chief negotiator Bruce Meyer that “the proliferation of COVID-19 outbreaks around the country over the last week, and the fact that we already know of several 40-man roster players and staff who have tested positive, has increased the risks associated with commencing spring training in the next few weeks.”

Regarding the implications of the outbreak on the season, the Phillies said “it is too early to know.”

The players’ union proposed a 70-game regular-season schedule Thursday, a plan immediately rejected by baseball Commissioner Rob Manfred. The sides are 10 games and about $275 million apart. The sides had talked about having opening day on July 19.

“MLB has informed the Association that it will not respond to our last proposal and will not play more than 60 games," the union said in a statement Friday night.

Philadelphia became the first big league team known to be struck by the outbreak. Three staff members at the camp also tested positive, and the Phillies didn’t identify any of those affected.

Florida has experienced rising incidents of new cases and rates of those testing positive for COVID-19. Over the past two weeks, the rolling average number of daily new cases in Florida has increased by 1,422.7, or 144.4%.

The Phillies said the first confirmed case occurred Tuesday. The club said eight staff members have tested negative for the virus, while 12 staff members and 20 players — both major leaguers and minor leaguers — living in the Clearwater area are being tested.

The Phillies closed their facility in March when the coronavirus pandemic shut down sports. Players returning from injuries were allowed to continue their rehab after the facility was cleaned thoroughly. A few of the team’s athletic trainers and staff remained to supervise and safety precautions were taken.

Several more players began working out at the facility over the past few weeks but group sizes were limited.

In a statement, managing partner John Middleton said, “The Phillies are committed to the health and welfare of our players, coaches and staff as our highest priority.”

“As a result of these confirmed tests, all facilities in Clearwater have been closed indefinitely to all players, coaches and staff and will remain closed until medical authorities are confident that the virus is under control and our facilities are disinfected," he said.

The World Series champion Washington Nationals, who didn't reopen the spring camp they share with Houston after closing their portion in mid-March, said they'd had one minor league player test positive at their facility in the Dominican Republic.