The 23-year-old last appeared for Cheltenham Town in the EFL, while also enjoying a spell on loan in the National League with AFC Fylde.
He began his career at Rochdale, before earning a big move to Norwich City, later spending a loan period with Dutch club SC Telstar.
Adshead has put pen-to-paper and is contention to make his debut against Forest Green Rovers on Saturday, having been allocated squad number 25.