Toronto FC and the Vancouver Whitecaps say no one at their club has tested positive for COVID-19.
The Montreal Impact, who announced in mid-April that a club employee had tested positive, did not want to discuss the issue.
"We are not commenting on our results," a club spokesman said Monday.
Major League Soccer said Sunday that 18 MLS players and six club staff had received positive Polymerase Chain Reaction (PCR) tests prior to travelling to Orlando for the MLS is Back Tournament.
As of Sunday, a total of 668 players had been tested since early June.
COVID-19 testing for MLS players and staff ramped up with the resumption of full team training earlier this month, with more tests mandated on the eve of departing for Orlando. Upon arrival in Florida, everyone is required to immediately take another PCR test and remain quarantined until they receive the results.
The league said 25 of its 26 clubs were able to commence full team training prior to travelling to Orlando for the World Cup-style tournament, which runs July 8 to Aug. 11 at Disney's Wide World of Sports complex.
The San Jose Earthquakes, the lone team unable to resume full training in their home market due to local health authority restrictions, were the first side to arrive in Florida — touching down last Wednesday.
"Some of the things have taken a little bit to get used to but I already feel like I'm at home here," San Jose defender Tommy Thompson told a media Zoom call Friday.
"It was a little bit intimidating at first but now guys are already starting to feel more and more comfortable," he added.
The league said Sunday that of the 329 people given PCR tests on-site in Florida, two were positive — both players who had just arrived. Anyone who tests positive while in Orlando is moved to the isolation area of the hotel until they get medical clearance.
Florida reported 9,557 new cases of COVID-19 among state residents on Friday although that number had dropped to 5,409 on Sunday, according to the Florida Department of Health, Division of Disease Control and Health Protection.
Orange County, which includes Orlando, reported 345 new cases among Florida residents on Sunday.
MLS suspended play on March 12, two weeks into the season, due to the global pandemic.
This report by The Canadian Press was first published June 29, 2020.
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Neil Davidson, The Canadian Press