The Millers’ club record signing followed up his derby winner against Leeds with a goal in Tuesday’s 3-3 draw with Fulham, showing more evidence of why Evans moved to sign him on September 1.
Despite the 20-year-old making a name for himself, the Millers’ manager believes his time will come further down the line in his development, just as it did for Kieran Agard last season.
Evans said: “I think there’s a lot more to come and he has staggering potential.
“He was a little bit quiet in the Fulham game and perhaps his runs were not as purposeful.
“But he is such a talented boy and probably the only player in our squad who could have scored that goal on Tuesday.
“I said to my chairman it would be a year for Kieran Agard and records say I was right, and when we signed Jonno I said it would be 18 months before we had him right as he’s just left his teens and is four or five years younger than Kieran and has a lot to learn.”
The successful elevation of Clarke-Harris has helped fill the void following Luciano Becchio’s untimely heel injury and return to Norwich City for treatment.
But Evans has confirmed that the Millers remain in the loan market and while acknowledging he has striking options already, bringing in another forward to boost his numbers represents the ideal scenario for him.
He said: “We have strikers who can step into the role, but we have always said we would like to work with another striker. As it is not going to be Luciano, we are looking now.”