Since taking out a licence, Skelton has made great strides in the National Hunt world and worked his way up to near the top of his profession in no time.
However, he has only saddled seven runners on the level and has yet to cheer home a winner.
Hestina has been in great form over hurdles, winning three of her last four, but she has not run on the Flat since winning her final outing for Peter Chapple-Hyam in October.
"She stays well and she'll go in the ground, but other than that I haven't got a clue how she'll run," said Skelton.
"Obviously she's been running well of late, but this is a completely different kettle of fish.
"It's quite clear we're trying to nick a bit of black type, but there are 16 runners so it's not going to be easy.
"If she finishes 10th I won't say I'm disappointed because I honestly have no idea what to expect.
"I did notice she ran in a Listed race for Peter Chapple-Hyam, but that was on fast ground, which wouldn't have suited her.
"So, she could win or come last, but unfortunately until she runs I'm none the wiser as to which of those is more likely."
Groovejet was second in the Park Hill Stakes for Chapple-Hyam but has been hurdling for current trainer Richard Spencer.
She was due to be a broodmare by now but things have not quite gone according to plan.
Owner Phil Cunningham bred her himself, out of his 2000 Guineas winner Cockney Rebel.
"She holds a big place in my affections and has been second in a Park Hill in the past," said Cunningham.
"A mile and six is probably her ideal trip, but hopefully she'll be OK over this bit shorter (a mile and a half).
"She was probably the most fertile mare I've ever had in her younger days, but unfortunately we sent her to Camelot and she didn't take, so we brought her back into training.
"The main aim is the Park Hill again and we thought we may as well take this in along the way.
"Jenny Powell rides a bit for us, had a nice winner the other day and we thought it would be nice to give her the ride in a nice race."
Three fillies bring a rating of 100 into the contest. Ralph Beckett's Isabel De Urbina, Hugo Palmer's Apphia and John Gosden's To Eternity.