The 21-year-old has not played since suffering a knee ligament injury in a pre-season friendly last summer.
He is back in light training and interim manager Paul Warne is hoping he will be fit to feature in the Millers’ final six games of the season .
“I think he’s about two-and-a-half weeks away from full contact,” said Warne.
“Today he was training predominantly with the squad but they can’t tackle him, which suits him as a centre-forward. He can just turn and shoot whenever he likes!
“He needs full contact and a couple of ‘ressie’ games and then he’ll be available for selection, if everything goes well.”
Clarke-Harris, who was Rotherham’s record signing when bought from Oldham in 2014, netted six goals in 37 appearances last term.
Warne added: “Although he’s at the end part of his rehab, it’s the most important part.
“We’re doing everything we possibly can to get him over the finish line. I think he will be available for the last five or six games.”
Bottom-of-the-table Rotherham look doomed to relegation, 16 points adrift of safety with just 12 games remaining, ahead of today’s visit from Steve Bruce’s Aston Villa.
Warne wants to see the Millers complete the season playing attacking football and trying to enjoy what could be their last few weeks in the Championship.
“I’ll put out the most attacking team I can, although I won’t go completely reckless,” he said. “I won’t put six up front.
“But we’ve got to score goals because we concede. If we don’t score two, we’re not going to win.
“That’s sort of how I’m planning to send the lads out.
“I want them to enjoy playing for me and the club and have a right go. If they do that and they lose, they won’t be berated by me.”
Relegated from the Premier League last season, Villa have struggled to adapt to life in the Championship, though Warne watched them beat relegation-threatened Bristol City 2-0 in midweek .
He said: “Games like these are the ones you want to be involved in.
“They’ll bring a big following, which suits us. If there’s a really good away following, it usually gets our fans more up for the match.”