Craddock has been named in a 13-man squad that does not feature first-choice leg-spinner Adil Rashid, who has an abrasion on his spinning finger.
The Huddersfield-born Craddock, 26, has impressed in the Yorkshire second XI having been on trial at the county.
He is one of four men who could make their Yorkshire T20 debuts tonight, along with pace bowlers Ben Coad and James Wainman, plus all-rounder Matthew Waite.
With Yorkshire all but mathematically out of the competition (defeat tonight would confirm their elimination), Gillespie has rested captain Andrew Gale and all-rounder Tim Bresnan ahead of Sunday’s County Championship match against Worcestershire at Scarborough.
Yorkshire are 14 points clear in the Championship with two games in hand on second-placed Middlesex, but their Twenty20 form has been contrastingly poor.
The county are second-bottom of the North Group after seven defeats in 12 games.
On paper, tonight’s match (6.30pm start) is a road trip Yorkshire could do without, with their final group fixture at home to Birmingham next Friday another likely dead rubber.
But pace bowler Liam Plunkett said that, if nothing else, Yorkshire plan to use these games as preparation for the Royal London 50-Over Cup, which starts for them on Sunday week at Scarborough.
“With the one-dayers coming up, it’s vital that we improve our skills with the white ball,” said Plunkett.
“The Twenty20 games offer us a good chance to practice against some good players and against teams that can still qualify, or have qualified, in Birmingham’s case.
“Brendon McCullum is with Birmingham, and that will be a good test.
“A couple of wins, and we’ll have some momentum going into the 50-over matches.”
Yorkshire (from): Bairstow, Carver, Coad, Craddock, Fisher, Gibson, Leaning, Lees, Maxwell, Plunkett, Rhodes, Wainman, Waite.