He said: "It's easy to understand why. If we win then we go into 2003 with a European competition to look forward to whereas at the moment you wonder whether the players have their minds on the Manchester United game. I hope they don't and I don't think they will but we have to adapt our minds.
"The best way to prepare for Manchester United is to play to the maximum in this game and win it. But having to adapt to this game is the big thing.
"We never play with our minds on another game but the United match is less than two-and-a-half days after this one. It's a very short period.
"We are looking forward to these two games because they mean a lot in our minds and to our season.
"Manchester United at Anfield is one of the biggest games of the season but they all have to be aware that the Vitesse tie is a difficult one."