The players in question didn't clear the NBA's initial quarantine in Florida and were placed in isolation away from the Disney campus.
Houston Rockets star Russell Westbrook said he had tested positive, though he hasn't yet joined his teammates in the Orlando area:
Sacramento Kings forward Richaun Holmes also announced he will be in quarantine for eight more days after mistakenly leaving the NBA's "bubble" to retrieve a food delivery.
The MLS Is Back tournament has underscored the difficulty that can arise for sports resuming during the pandemic.
MLS brought its 26 clubs to the ESPN Wide World of Sports Complex in Bay Lake, Florida, to stage a knockout tournament ahead of restarting its 2020 season.
FC Dallas and Nashville SC withdrew from the event after they had multiple players test positive for COVID-19. MLS also postponed a match between Toronto FC and DC United after one player tested positive and another player's test yielded an inconclusive result.
ESPN's Tim Bontemps outlined the NBA's coronavirus protocol in June. Players and team staffers were tested every other day starting June 23. Upon reaching Disney, they had to test negative twice over a period of more than 24 hours to receive clearance to travel and work out in the NBA's campus.