Charlie Barnett, Aidan Chippendale, Bohan Dixon and Tom Eckersley will all be released by the League Two outfit.
Further departures could yet be made with a number of players still in negotiations about their futures.
Midfielder Barnett made 102 appearances for the club after arriving from Tranmere in 2010, but featured just three times since January as the Reds avoided the drop out of the Football League.
Winger Chippendale made just four starts after signing in the summer, while midfielder Dixon made eight appearances before leaving for a loan spell with Evo-Stik Premier side Marine.
Former Bolton defender Eckersley played just four times and had loan stints at Blue Square Bet Premier sides Barrow and Stockport.