That brings to six the number of players who have tested positive for COVID-19 since arriving at Orlando next Wednesday's kick off.

All 26 MLS teams are set to stay in a 'bubble' and will play matches without spectators at Walt Disney World.

No specific teams or players were identified, but the league said that in the past two days, a total of 392 players, coaches, referees, MLS staff and club staff had been tested in the past two days at the host hotel to detect the four positive cases.

Two players had tested positive from 329 prior Orlando tests, MLS had announced on Monday.

Before traveling to Orlando, all MLS players, coaches, referees, league and club staff were required to have two negative tests 24 hours apart.

Another test is given when each team delegation arrives and all people are quarantined until the results of that test are known.

The players who tested positive have been moved to an isolation area of the hotel.