Jersey Bulls lost out in the Combined Counties Premier South play-off last month after losing at home to AFC Croydon Athletic.
They finished second in the ninth-tier league in their fifth year of existence.
“Gary leaves behind a well established squad who know the ins and outs of the league,” added Powell.
“That experience will be vital as we look to add in a few fresh young players to boost the current playing squad and slowly transition into a new, hopefully even more successful, era for the side.
“Obviously, the ultimate goal is promotion but we have some work to do.
“We have a number of senior players who won’t be around forever and we need to embed youngsters to ensure longevity to the competitiveness of the side.”
As well as his work with Jersey’s island side Powell led St Peter to the Jersey Premiership title and Upton Park trophy in a four-year spell in charge.
“I’m also keen to use my experience of local club football to ensure a positive, productive and supportive relationship between the local clubs, the association and the Jersey Bulls,” he said.
Jersey Bulls chairman Russel Le Feuvre added: “We owe so much to our exiting Manager Gary Freeman and his management team for their unwavering dedication and achievements in their tenure, ending in our most successful season to date,”
“As a club we are committed to creating meaningful pathways for Jersey players, coaches and referees.
“Next season will no doubt be another testing time and it’s great to see the footballing, and wider community embracing and supporting the island as it competes in the English National League system.”
