Stephen Bywater, Dean Leacock and Stephen Pearson are all seeking new clubs and, once they are sold, it should free up around £25000 a week off the Pride Park wage bill.
Goalkeeper Bywater, 30, has been out on loan at Sheffield Wednesday and a permanent move to Hillsborough is in the offing.
Pearson, 29, meanwhile, is at Bristol City and it is thought likely the Robins will sign the midfielder.
Leacock, 27, though, is in limbo, with no clubs as yet showing an interest in the injury-plagued centre-half.