The Blues face an exhausting schedule with five matches in 13 days - starting with Southampton in the league today and the FA Cup quarter-final replay against Manchester United at lunchtime on Monday.
Benitez said: "In terms of preparation or tactics, we will be fine.
"Physiologically, it will be impossible. A day after a game you are tired. Two days, you are even more tired.
"This second day will be really tough for everyone.
"We then have three days before Rubin Kazan. Three days is very close. Four days is fine."