The 21-year-old striker has been on loan at New York Stadium from Newcastle since November but has made only eight starts, with Evans preferring to use him from the bench.
But Evans thinks he could come to the fore in the final few games of the season and the forthcoming play-off campaign.
"He has got a different way of playing, I was impressed with him in training and it was a big decision not to start him against Bradford," Evans said.
"Chance apart, and it is a big chance, I thought he caused them mayhem. When he renewed his loan at the end of January I knew in the big games at the end of the season he would be a big player for us and I still firmly believe that."
Ahead of the game at Wolves on Good Friday, the gaffer, who plans to make a few changes to freshen up his side in the final four league matches, isn't too concerned about sides trying to stop them scoring after last Friday's 0-0 draw.
A dominant display against a particularly unadventurous Bantams outfit saw only a host of missed chances cost the Millers the win.
Evans added: "Playing 4-5-1 with 11 men behind the ball and setting up to defend is not the way we play, but it takes all types to win a game of football.
"Who's to say we are not going to score, who's to say we are not going to get the penalties, who's to say if we score early teams won't have to be more creative?
"We'll expect to have a good campaign, but Simon Grayson (Preston) is well known for preparing a side to do well in the play-offs and Leyton Orient are a very good team. We are the underdogs, we are the little one in the pile that people don't think should be there."
Source PA