Chandler, who was part of the club's historic run to the FA Vase semi-final last season, has left The Victory Stadium to link up with Hampshire Premier League Senior Division side Moneyfields Reserves.
His sudden move away from the club leaves boss Grice short in the right-back department, although the USP boss did reveal he’s optimistic over adding an unnamed player to his squad prior to Cowes' visit on Saturday.
US Portsmouth have hit somewhat of a rough patch in recent weeks, losing each of their previous four Wessex League Premier Division matches and five of their past six fixtures in all competitions.
But Grice says his squad are buoyed to put on a performance and grab a much-needed victory against Cowes in what will be their final fixture before a tricky trip to current leaders Horndean on January 4.
Grice said: ‘It’s a bit of a weird time, obviously we’ve got Christmas coming up, and we’ve got some time off over Christmas so it’s kind of like a last call before Christmas to get everyone up for it.
‘Jack Chandler has left to go and play for Moneyfields Reserves. He was our right-back at this moment in time but he’s left.
‘The lads that we’ve got in, we’re all upbeat, we’re looking forward to the game on Saturday just to try to win a game.’
A tough recent run of results has seen US Portsmouth slip down to 17th in the table.
But Grice retains the confidence in his current crop of players to get them rising up the table again.
He added: ‘I think we’ve got the players that we need to get some results. Obviously we’re going to have to be at our best on Saturday to get it (win).
‘It’ll be interesting to see how we get on against them. It’s a fairly local game for them (Cowes), we’re probably the nearest club they have to play. Everyone is more than up for it and we’ll just have to see what happens.’