A member of the coaching staff and a member of the home clubhouse staff received the positive test results, the team said.
In a statement issued Thursday, the Phillies said no players received positive results from Wednesday's testing.
Blue Jays manager Charlie Montoyo said concerns about those positive tests led to the series being called off, the AP reported.
"Our plans right now are to stay put and let MLB work through whatever they're working through," Montoyo said before his club played the last of four games in Washington. "We're not going to Philadelphia. Those games have been postponed," he said.
The Phillies said all activity at Citizens Bank Park has been canceled Thursday and until further notice.
🚨BREAKING: Phillies have 2 staff members that tested positive for COVID-19— Jeff Skversky 6abc (@JeffSkversky) July 30, 2020
One is a member of the coaching staff and one is a member of the home clubhouse staff
All activity at Citizens Bank Park has been cancelled today and until further notice.@6abc #Phillies pic.twitter.com/MLkHlb4KOX
The weekend series against the Blue Jays would have included a doubleheader on Saturday.
Earlier Thursday, word emerged that another player with the Miami Marlins - who recently played at Philadelphia - tested positive for COVID-19, bringing their total outbreak to 17 players, according to a person familiar with the situation told the AP.
On Wednesday, general manager Matt Klentak said an employee who works in the visiting clubhouse tested positive.
The Phillies' four-game, home-and-home series against the New York Yankees was postponed this week following a coronavirus outbreak among the Miami Marlins, who played a season-opening series in Philadelphia last weekend.
The Blue Jays are stuck on the road because the Canadian government wouldn't let them use their stadium in Toronto this season because of fears about teams traveling back and forth to the United States. Eventually, the Blue Jays are supposed to play home games at a minor league ballpark in Buffalo, but it isn't ready.
Miami's team remains quarantined in Philadelphia, where the Marlins' outbreak was discovered during a weekend series against the Phillies. Two Marlins staff members have also tested positive. The person who spoke to The Associated Press on Thursday about the Marlins did so on condition of anonymity because test results were not announced. Miami's season has been suspended through at least Sunday, and it appears the schedule will be altered next week, too.