The news comes after three more unnamed Rovers players tested positive for Covid-19, with the results announced on Monday evening.
The December 29 trip to the Highbury Stadium and the game at London Road to start the New Year on Saturday (January 2) and the January 5 appointment at Oxford's Kassam Stadium will now be rearranged.
A club statement said: "Following the announcement of two confirmed cases on Boxing Day, the club can confirm that – after a round of testing – a further three players have tested positive for the virus with all players observing a period of isolation in line with EFL and government guidelines.
"The club has therefore informed the EFL that it is unable to fulfil its upcoming three fixtures.
"The safety and health of Rovers’ players and staff is of paramount importance and the club has implemented and followed wide-ranging and comprehensive protocols to protect its players and staff."
Doncaster called off the scheduled Boxing Day home encounter with Accrington Stanley due to two positive tests among the club's playing squad, with others displaying symptoms.
Test results have now revealed the additional positive cases.
In November, Rovers' coaching staff were forced to miss two games because they had to isolate for a fortnight after coming into contact with AFC Wimbledon employees who tested positive.
Doncaster's next scheduled match is due to be on January 9 when they visit Blackburn Rovers for an FA Cup tie.
Covid-19 isses had earlier forced the postponement of Hull City's League One home game with Lincoln City on Tuesday (December 29).