The Sharks are looking to make it four on the bounce having won their last three games in the competition, their latest success a comfortable 95-run victory over rivals Surrey at The 1st Central County Ground on Sunday.
That left them second in the south group, with the top four qualifying for the quarter-finals when the group campaign ends next week.
Chris Nash (82) and Harry Finch (61) both made half-centuries as the Sharks made 300 for 8 from their 50 overs, before going on to bowl out Surrey for 205 in the 42nd over with David Wiese claiming figures of 4 for 29.
The Sharks are sitting in second spot in the South Group table, a point shy of leaders Somerset. Finch and Laurie Evans are currently neck and neck at the top of the Sussex batting charts, both having scored over 200 runs so far, whilst Wiese is the leading Sharks wicket-taker with 11 scalps.
Sussex have named an unchanged 13-man squad for tomorrow with Michael Burgess, who claimed three catches on Sunday including a stunning effort to dismiss Ben Foakes, continuing to deputise for gloveman Ben Brown who is still ruled out with the fractured finger he suffered at Kent.
The Sussex squad is as follows:
Michael Burgess (wkt)
Stiaan van Zyl
Luke Wright (c)