The 25-year-old ended last season on loan with League Two Carlisle, scoring four goals in 19 appearances.
"For the way we want to play we do need a target, someone up top who can bring other players into the game," boss Paul Warne told the club website.
"I told him that I felt that he has underachieved so far in his career with what he has got in his locker."
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Rotherham United have signed Bolton Wanderers striker Jamie Proctor for an undisclosed fee on a two-year deal.