The Northern Ireland international signed for the Yorkshire side this summer after three years at Scunthorpe, but a groin injury suffered at the start of July means he will only make his debut in Saturday's pre-season friendly with Hearts at New York.
"The kid has worked so hard in the last three weeks that everyone inside Rotherham United is willing him to do so well. He is now fitter than he has ever been and looking very sharp too," said Evans.
"Michael is a top class player and our supporters will take to this lad in a very big way.
"He is a real competitor and can certainly play. His passing is very assured and I know when he is on top of his game we will win matches. This lad is a Championship player every day of the week."