How wide can you make the bubble around the teams? Are the teams going to test the minor league players every other day to ensure that when they bring in replacements, they are virus free?
They could bring in replacements for during the period players/managers have the virus, but they wouldn't be able to replace them fast enough to not miss any games. If a replacement is necessary, they would have to be tested and it would take a day to get the results back. That roster spot would probably be vacant for 1 or 2 games. They could probably play that way with 1 or 2 players testing positive. If the number gets to 6, or especially 19 it would become very difficult.