Ahead of today's clash with Brentford, Evans revealed Van Nistelrooy has made an attempt to lift the players after a poor run of form.
He said: "You can take the positives from that, we want to add more goals and I guess you always have to look at things positively. The outside noise should not influence you.
"Ruud van Nistelrooy spoke the other day about it being a game and going back to playing football when you are a child and you go on the pitch to compete. I think everyone wants to get to that new place where you are not influenced by the outside noise and you can go on the pitch and give your best every week.
"I think every player, every weekend, tries to achieve that: to play with pleasure and with a smile on their face. Of course we expect to win games and every time you win it is always more enjoyable."
Evans also said: "Hopefully we'll score more goals and the results will improve. The defensive aspect has improved and that's been positive. So I think that's something that the manager has addressed and that, when we come back after the international break, we want to look at, and it's not always just the strikers. I think we're positioning ourselves well.
"Our final ball needs to be better and once you get a goal or two and start to gain confidence in the games, you can be a little bit more patient in the opposition box and pick the right path and be careful."