The 27-year-old Nottingham born striker had been transfer listed by the club and had fallen well down the pecking order at The Proact Stadium.
Westcarr and Chesterfield had been keen to come to a deal regarding a permanent switch of the frontman to The Banks's and it now seems both side have agreed to part ways.
Craig spent a month on loan at Walsall and is expected to pen a deal until the end of the season.