And Moore says he's been impressed and that Cresswell can only get better.
He told the clubs official website: "Ryan has played a lot of games over the past two seasons.
"He is a young kid with some good leadership qualities and he is a winner. When I went to see him I was impressed. He was pointing and shouting at strikers, telling people to hold the ball and that is the type of player we want.
"Ryan is a Rotherham lad so he wants to play for his hometown club so there are plenty of positives and at 22 he can only get better," added Ronnie.
"I thought that we were a little short down the middle last year and the two centre halves mostly had it all their own way. We didn't have enough cover so I am hoping to get that right this season."