Andrew Frampton, Deon Burton, Tommy Forecast and Joe Carter have been given the chance to stay at the club, but Lewis Montrose has been told he can leave.
Meanwhile, Danny East will be brought back on a pre-season trial so Allen can assess him further.
Allen told the club's website: "Andrew Frampton and Deon Burton have both done very well for us on and off the field. They are model professionals.
"Their contracts are up and between us we will work out to see if they can stay with us for next season. They will both be offered new deals.
"Tommy Forecast will also be offered a deal as he has been given a free transfer by Southampton. Danny East is available on a free but I have not seen enough of him to offer him a contract and I have invited him back for pre-season training to see if we can give him a contract.
"Joe Carter has been offered one more year as he was doing very well up until he got injured and we need to see him out on loan playing men's football.
"Lewis Montrose has been injured now for a while and we have done all his rehab. He is a good player and a great person and Lewis will continue with us through the summer to get him fit, but Lewis will not be offered a new contract with us.
"No doubt he will find a new club but if he doesn't he can train with us for three weeks of pre-season because Lewis played an important role in us becoming champions."