The News understands he is poised to leave Westleigh Park just weeks after agreeing a new contract with the club.
Mike Carter, Theo Lewis, Ryan Woodford and Ed Harris have already departed following the appointment of new manager Paul Doswell earlier this week.
It is believed Ben Dudzinski, Jordan Rose, Chris Paul and Josh Huggins are set for a similar fate.
Since his arrival, the new Hawks boss has outlined his commitment to three extra morning training sessions for next season.
It is understood that is a factor in Williams’ impending departure – along with Carter’s move towards the exit.
Ex-Pompey midfieder Wes Fogden is still in negotiations with the club.
Meanwhile, the sudden turnaround in the Hawks’ squad has led them to pull out of forthcoming Portsmouth Senior Cup final.
Despite being reigning champions, the Westleigh Park outfit have decided against defending the silverware.
Hampshire League side Paulsgrove will now face Moneyfields at Fratton Park on Tuesday, May 21.