The 30-year-old played an integral part in the Millers' promotion from League Two last season, winning the club's player of the season award.
Although his presence up front wreaked havoc for opposition defenders he was only able to score six times.
However, that did not stop Evans, who turned down interest in Revell last summer, handing him a new two-year contract and the boss believes his striker can hit double figures in the second tier.
"I wouldn't have given him a two-year contract at the end of last season if I didn't think he would be a handful," said Evans.
"This football club could have taken money for Alex many times, but I had a real belief when I came in that he was one of the players I wanted to go with.
"Alex will get better, we have started to work with him on his ball retention and getting in the box.
"He had a tendency to want to link the play in the second phase and not the third phase and that's why his goal ratio was poor, but when he was in League One at Leyton Orient he got 17 or 18 goals and he can do the same again with us."