Guernsey director of cricket Ashley Wright plans to use the Sussex Premier League to get the island's youngsters ready for the senior side.
The Sarnians have entered Division two and beat Bognor Regis by 123 runs in their opening match.
"I hope we do well in the competition, but the main thing we're using it for is a development process," Wright said.
"We want to get our players over there and fast-track them a bit, especially the younger lads coming through."
The agreement was struck last year by Guernsey chief executive Mark Latter and board member Dave Brooks, who used to be chief executive at Sussex County Cricket Club.
Guernsey are set to take part in World Cricket League Division Five, which starts later this month in Jersey.
"It's slightly more competitive cricket over there (Sussex) - hopefully it'll fast-track our players on an individual basis and as a team going forward," Wright told BBC Sport.
"What we took at the weekend was the squad which is going to Jersey, so we used it as a bit of prep for the tournament.
"At the moment all our prep is towards the World Cricket League, that's our main focus."