Rafael Benitez says he is "really surprised" Everton will play Burnley on Boxing Day with the Merseyside club having only nine senior outfield players fit to play.
A Covid-19 outbreak at the club and a six-man injury list were the reasons Everton requested to the Premier League postpone their game against the Clarets, but it was rejected.
Benitez says fulfilling their Boxing Day fixture "is not fair".
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"I am really surprised we are playing this game," he told reporters.
"We have followed all the rules, we have done lateral flows every day, we do the PCRs and we have worn the masks. We have players in three different dressing rooms [to reduce the risk of transmission].
"But we cannot control if you go to a game, if a player is positive but has not got any symptoms, he can pass the virus to the others. After we played against Chelsea, we found we have five positives.
“We have nine outfield players and three keepers. And then we have to bring five new young players into the team, who are not even 21 years old.
"We have players who have knocks and we have to push them. Dominic [Calvert-Lewin] has been out for two months and maybe has to play for 90 minutes. It is a massive risk."
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Everton have won just two of their last 12 matches in all competitions and are 14th in the Premier League table on 19 points. Benitez says he will have to think hard about how he can field a competitive starting XI to play Sean Dyche's side.
"We have to wait to see which players are available," he added.
"It is a difficult situation. When you talk about what is going on and the number of COVID cases in the country, we will have more and more cases every day.
"I don’t know the conditions of every club. I know our situation, we have six injuries, five players with COVID and now we have to pick players who have been out for a while or young players, and we have to take a risk putting them on the pitch and possibly in different positions.
"It will not be easy and I think it is not fair.
"What teams around Burnley and around us [in the Premier League table] will think in terms of the integrity of the league, I don’t know. Clearly, in this case, it is a surprise that we have to play this game.
"Now, I have to think about if I have 11 players fit and where can I put them."
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