Butler had previously worked with Dickov at the Scot's ex-club Oldham before taking up a coaching role under Paul Ince at Blackpool.
"The two years I spent with Paul (Dickov) at Oldham were invaluable for me as a young coach," Butler told the club's official website.
"The remit of my job at Oldham was a really good learning experience for me. It was an internship, if you like, at senior level professional football. I had a lot of responsibilities and was exposed to a lot of different situations.
"It was a really good experience and I've built up a fantastic relationship with Paul and we work well together so when he called me about the opportunity here it wasn't a difficult decision to make.
"I am young for a first team coach but I don't think age is an issue. I think if you're good enough you're old enough and Paul has given me this opportunity to prove that."