Mascherano's departure for what Benitez considers an unnecessary friendly against the African Cup of Nations' champions, four days before the Merseyside derby with Everton and a week ahead of the Champions League quarter-final first leg at Arsenal, is therefore a major concern for the Liverpool manager.
"I am really, really happy that Mascherano must go to Egypt to play a friendly," said a sarcastic Benitez, who also loses the midfielder to Argentina's Olympic squad in August as one of their three over-23 players. "Things like that you just cannot understand. There is nothing you can do. The rules are the rules and the players must go.
"You can't speak to the coach. You can say 'Be careful' but they are thinking about themselves.
"They need to check the players to see if they can manage with the team, so it will be very difficult. It's the same problem for all the top sides. Normally the best players are in the top sides and they are playing Champions League or playing for the title."