The 22 year-old signed for the Millers after being told he will be released by Newcastle, and the club beat off hot competition for his signature from elsewhere.
"He's a Championship player all day, he's not a sitter, he goes box to box with great technical ability", said Evans to themillers.co.uk.
“We’ve worked hard to get Conor in, he’s a player I’ve seen play in Scotland after he originally impressed me for Newcastle United’s Under 21s when Steve Stone earmarked him.
"He went up to Scotland and I’ve seen a number of games, and then he’s been on his holidays this week weighing up his options so we’ve made our pitch and I must say it's helped when he's good friends with James Tavernier (on loan with Rotherham from Newcastle).
“He’s been finished a few weeks and he could be away with his holiday commitments,but he wanted to make a decision and we’re looking forward to working with Conor.”