Swindon's League One fixture at Oxford United on Saturday has been called off because of "a number of positive Covid-19 cases" at the Wiltshire club.
A statement said the decision was made after "concerns were raised over the potential risk of further infections".
The English Football League (EFL) has said the circumstances surrounding the postponement will be investigated in accordance with its regulations.
It is the second EFL fixture scheduled for this weekend to be postponed.
Eight Accrington players returned positive test results, causing the cancellation of their League One home game against Bristol Rovers.
Meanwhile, on Thursday, National League club Notts County withdrew from their FA Cup fourth qualifying round tie against King's Lynn Town after six players tested positive for coronavirus.
No new date has been confirmed for the rearranged fixture between Oxford and Swindon.