Laurie Evans will now join Surrey on loan for the rest of the 2020 campaign, before signing for the London-based club on a permanent basis at the end of the season.
It was initially announced that the batsman would pull on the Sharks shirt for the Vitality Blast before heading to The Kia Oval, but Evans made his desire and preference to join Surrey for the Vitality Blast clear.
Evans is not permitted to play against Sussex in either the Blast or the Bob Willis Trophy this year as part of the loan agreement.
Sussex head coach, Jason Gillespie said: “From a club point of view, we’re obviously disappointed.
“Laurie made it clear he was keen to start his time at Surrey. It therefore made sense for all parties to allow him to play for them now.
“With Laurie preferring not to play for our team, it allows another player the opportunity to represent Sussex in the Vitality Blast.
“Laurie has performed well for us in one-day and T20 cricket in the past, and we wish him well for the future.
“Our focus now is on our players and to prepare them in the best possible way to allow us to challenge for success in the Blast.”