Scunthorpe boss Nigel Adkins has offered new deals to Steve Foster, Jim Goodwin and Richard Hinds. But veteran striker Steve Torpey, 36, is to be released after seven years at Glanford Park, along with midfielders Neil Mackenzie and Ashley Alanson.
Meanwhile, Adkins is keen to secure the permanent signing of Leeds United frontman Jermaine Beckford.
The 23-year-old spent the second half of the season at Scunthorpe and scored eight goals in 17 starts.