A host of EFL games have been postponed during the past week.
Cardiff were scheduled to host Coventry in the Sky Bet Championship on Sunday but they have “several cases of Covid-19” among their playing squad and staff.
Northampton were set to play at home to Walsall in League Two, while Newport were due to take on leaders Forest Green in the same division.
A host of EFL games have been postponed during the past week following an increased transmission rate of the Omicron variant.
A Cardiff statement read: “Following consultation with the EFL, Cardiff City regret to announce that Boxing Day’s fixture with Coventry City has been postponed due to several cases of Covid-19 within the playing squad and staff.”
Cardiff’s scheduled game at home to Derby this past weekend was also postponed, as was Coventry’s meeting with Stoke.
Earlier on Monday, Northampton and Forest Green each announced their forthcoming weekend games were off due to coronavirus issues in their respective squads.
Table-topping Forest Green, who sit four points clear of the second-placed Cobblers, have now seen their last three fixtures called off.
Of the six clubs affected by the latest postponements, Newport were the only team in action on Saturday, losing 3-0 at Rochdale.