Relegated League One side Wrexham have released Andy Dibble, Scott Green and Chris Armstrong, while Brian Carey has the summer to prove his fitness if he is to win a new contract.
Both Green, 35, and striker Armstrong, 33, have seen their season blighted by injuries.
The same can be said for the ageing Dibble, who has missed the best part of two seasons with a broken arm and a thigh problem, and the Denis Smith has added Sunderland keeper Mike Ingham to the squad.
On releasing the players Smith said: "Andy's been a great servant, but he's been injured and it's getting to the stage where it's harder for him to get fit.
"If I can do something for him where he comes in on a coaching basis then I will.
"Scott has done a good job since he came here on a short-term basis.
"Chris' goal-per-game ratio has been good, but he hasn't played enough - and in the end I have to make decisions on that."