The Premier League has postponed two matches on St Stephen's Day due to Covid-19.
Leeds' clash with Liverpool at Elland Road and Wolves meeting with Watford have both been called off.
It follows requests from Leeds and Watford for the games to be rescheduled.
Last weekend, a total of six fixtures were called off for similar reasons as the Omicron variant sweeps through the UK.
The Premier League's statement says that Watford were unable to field a team, while Leeds were also affected with Covid-19, illness and injury.
It comes as managers and captains in the top flight are set to meet later today (Thursday) to discuss the ongoing impact of the virus on the league.
Some have called for the fixture congestion to be eased - such as the Carabao Cup semi-finals taking place over one rather than two legs.
Premier League Statement
"Following postponement requests from Leeds United and Watford FC as a result of COVID-19, the Premier League Board met this morning and regrettably agreed to call off the two affected clubs’ Boxing Day fixtures. The two games are Wolverhampton Wanderers versus Watford FC and Liverpool FC against Leeds United, both due to be played on Sunday at 12:30pm.
"The Board today was able to make its decisions in advance of Boxing Day to give clarity to clubs and their supporters. We apologise for the inconvenience and disruption caused to those fans’ festive plans.
"The League is aware that the decision to postpone these two matches will disappoint supporters and understands their frustrations at a special time of year when fans look forward to attending and watching football games. The League aims to provide as much clarity as possible, but unfortunately postponements sometimes have to be made at short notice, as safety is the priority. The League will endeavour to keep supporters updated if games become at risk on a matchday.
"The Board concluded that Leeds United will not be able to fulfil their fixture this weekend due to the number of players with COVID-19, injuries and illness. The club’s training ground has also been closed after consultation with the UK Health Security Agency and the Premier League.
"Watford FC continue to have an insufficient number of players to field a team after their game against Crystal Palace FC last Saturday was postponed following a COVID-19 outbreak. Due to players coming out of isolation, it is fully expected Watford will be available for their fixture on Tuesday 28 December, against West Ham United.
"The Board assesses applications to postpone matches on a case-by-case basis, based on existing rules and adapted COVID-19 postponement guidance introduced to clubs in light of the new Omicron variant. The Board will assess a number of factors, including the ability of a club to field a team; the status, severity and potential impact of the COVID-19 outbreak at the club; and the ability of the players to safely prepare for and play the match. The Board must also consider the wider risks to the opposition and other people the club representatives may come into contact with.
"While recognising a number of clubs are experiencing COVID-19 outbreaks, it is the clubs’ and the League’s collective intention to continue the current fixture schedule where safely possible. The health and wellbeing of all concerned remains our priority and the League will continue to monitor and reflect public health guidance, always proceeding with caution. In light of the recent rise in COVID-19 cases across the country, the Premier League has reintroduced Emergency Measures. These include protocols such as more frequent testing, wearing face coverings while indoors, observing social distancing and limiting treatment time."