Twelve individuals from English Football League clubs have tested positive for coronavirus in the past week.
The EFL said eight cases came from six Championship clubs, with Brentford publicly confirming one case.
The other four positive tests came at two League One clubs, from which only the four play-off entrants were involved in the testing process.
There were no positive results from the tests at four League Two clubs.
More than 2,600 players and staff from EFL clubs were tested during the past week, including 2,213 connected to Championship teams.
Championship side Bristol City said on Tuesday that one person from their club had tested positive for coronavirus, while League One Oxford United confirmed on 12 June that two people had tested positive from their club.
Those who returned positive results must self-isolate away from their respective clubs, as per EFL guidelines.
Players and staff at EFL clubs are tested twice per week, with different protocols implemented dependent on the nature of the positive tests.
The League Two play-offs get under way on Thursday with two semi-final first leg matches, while Championship fixtures are set to resume on Saturday.