Two Championship matches and five League Two games on 26 December have been called off because of positive Covid-19 cases.
Cardiff's home game against Coventry and Stoke's trip to Barnsley have both been postponed in the second tier.
Five scheduled games in League Two have also already been called off.
Leaders Forest Green's trip to Newport is off, as is Bristol Rovers v Sutton, Northampton against Walsall, Bradford versus Harrogate and Exeter v Swindon.
These are the first seven games affected in the traditional Boxing Day programme.
More fixtures are likely to be postponed around the country as national figures rise following the effect of the Omicron variant, with daily lateral flow testing now taking place at clubs for all first-team players and staff.