Former Coventry City loanee Conor Henderson will not be offered a new deal by Grimsby Town.
Henderson is one of nine players who have not been offered new deals at Blundell Park.
Former City trialist Chris Day has signed a deal with Stevenage FC to become a player-coach.
Another former City trialist keeper Chris Neal, who was with the Sky Blues for pre-season in 2004, has signed for Fleetwood Town on a two year deal after leaving Port Vale.