St Paul's manager Paul Brannan has resigned because of work commitments as a community sports development officer.
Brannan, who took over as Saints boss at the start of last season, has led the club to victory in every tournament they have entered under his reign bar one - this year's Wheway Cup.
The club could win a fourth trophy this season in the Le Riche Cup final against Trinity on Wednesday evening.
"Unfortunately at some point something has to give," Brannan told BBC Sport.
"When I took the job I expected to see myself at the club for a minimum of three years, hopefully four.
"But your time is taken up hugely by the efforts for training sessions and all the work that goes on behind the scenes that people don't necessarily see and that, alongside your full time job. In my world my work commitments are becoming more and more busy."
|Paul Brannan's role of honour|
|Two Jersey league titles|
|Two Channel island club titles|
|4 wins from 5 cup finals - with a 6th on Wednesday|
He continued: "The fear was that later on next season things would be too busy and I'd have to speak to the club then about my concerns.
"It's better for the club and the players, although it wasn't a decision I wanted to take and wasn't taken lightly, it was better that I took it now so that the club could be well positioned for the start of next season."
Under Brannan, St Paul's have won two Jersey Premiership titles and two Channel Island club titles - including a record 9-0 win over Guernsey champions North in 2015.
The club has also won the Charity Cup twice and the Wheway Cup once.
Brannan will be replaced by former Jersey and Saints players Stuart Andre, Craig Leitch and Jordan Docherty next season.
"I can't think of three people better-placed to manage St Paul's," he added.
"They've been at the club since they were juniors and they know the club inside out. St Paul's is built on winning and they are three people who can't define winning any better."