'Keeper Shearer is ahead of schedule on his treatment programme after missing 8 weeks with injury, whilst Arnason and Agard could return for the next league game against Gillingham a week on Saturday.
Meanwhile loanees Courtney Cameron and Jack O'Connell have been given permission to feature in Saturdays FA Cup tie with Notts County.
Lee Frecklington is now fully fit after coming off the bench in Tuesdays win at Accrington as discussions continue about a permanent move in January from his parent club Peterborough.