The two Premier League rivals are to meet in the second leg of their quarter-final tie at Stamford Bridge on Tuesday, which Chelsea lead 3-1 from the first leg.
"There is a fantastic spirit around this club at the moment - everyone believes in what we can achieve this season and it is exciting to be a part of that," said the Dutchman.
"But we must not lose our focus for one game or one minute and that means each game is as important as the next one. We have the same aim, which is to try and win all of them.
"It is important that we take the momentum gained from winning at Anfield into this game and keep our level of performance up."