The West Brom striker has been a rare bright spot for the Cobblers this season and Boothroyd told BBC Radio Northampton: "He's shown me that with coaching, work and playing games, he's going to another level.
"He's nowhere near as good as he can be yet."
John Johnson's red card against Burton on Boxing Day has been overturned meaning he can play against Swindon Town on Saturday.
Michael Jacobs meanwhile has praised the impact Boothroyd has made at the club and insists he would be happy to stay at Sixfields despite speculation over his future.
The 20-year-old told the Chronicle & Echo: "If something happens, it will be down to the chairman.
"And if he does want to accept a bid, then it will be down to me.
"But I’m really happy here, the new manager has brought a new positive mindset to the club, so that isn’t really bothering me at the minute."