Boss Louis van Gaal expects a tough battle when Manchester United face Preston North End in the next round of the FA Cup.
The Red Devils eased past Cambridge United on Tuesday night to reach the next round of the competition with Juan Mata, Marcos Rojo and substitute James Wilson all on target in the 3-0 win.
And the Dutchman, who was happy with the second half performance, says the trip to Deepdale will not be taken lightly.
"I think it's always difficult to beat a lower team and you cannot do it well," van Gaal told MUTV.
"In spite of the 3-0 result tonight, you never do it well because everybody expects more.
"In the second half, I think we played better. We created many more chances but we didn't score. Robin van Persie had four possibilities to score, but [on the whole] I am pleased.
"I am [also] pleased to play against Preston North End now but also I know it shall be very difficult to beat them. Preston beat great cup fighters in Sheffield United.
"I have heard from Ryan [Giggs] they are very good fighters and Preston beat them 3-1 at home. So Preston will not be a piece of cake."
Striker Robin van Persie was taken off in the 65th minute of the game but the Dutchman reassured the fans that the 31-year-old suffered no injury problems during the game.
"It's always difficult to play three matches in a week," van Gaal explained.
"I have given rest to five players. I think that when we have won, after the match I can say it was a very good decision.
"I gave van Persie a rest during the match and also Di Maria, and I gave Ashley Young minutes to play because he is back again."
