The Spitfires, considered by some as one of the pre-season promotion favourites, endured a difficult campaign and ended up finishing 14th.
Hessenthaler will be targeting a much improved season next term and has announced his retained and released lists.
With 11 players already under contract for next season, the boss has decided to release five players.
Ayo Obileye, Gavin Hoyte, Harvey Read, Sam Togwell and Mark Childs have all been released whilst Ryan Broom and Sam Matthews have returned to their parent clubs after their loans finished.
Ben Williamson and Chris Zebroski have both had their contracts extended whilst Ben Strevens and Paul Reid will not be part of the playing squad and will focus on assisting Hessenthaler behind the scenes.
The Spitfires boss told the club’s website: “This time of year is always difficult when it comes to players out of contract. It's probably the hardest job as a manager.
"We looked at the squad in general and we had twelve players under contract for next season and we had two players who had an option on their contract for those to be extended.
"We had to release some players to release some additional funds to bring in new players. We had to look at the average age of the squad and bring that down.”
For more news, reaction and action from across the National League, like us on Facebook and follow us on Twitter and Instagram.