The five-year-old, owned by JP McManus, has finally been fulfilling the promise she showed as a juvenile when runner-up to the O'Brien-trained Alice Springs in a valuable sales race at Newmarket, when she was with David Wachman.
Clear Skies remained a maiden until November, since when she has chalked up five wins from her last six starts at Dundalk in a maiden and handicaps.
She is now stepped up in class and will be O'Brien's first runner on the all-weather in Britain since 2002.
"She seems to be in good form and we've been happy with her since her last run," said the Ballydoyle handler.
"She's been gradually progressing with every run and we've been delighted with her really."
It will be a first run on the all-weather for Khalidi as the four-year-old makes his debut for Clive Cox.
The son of High Chaparral was a smart three-year-old in 2017, winning two Listed races and finishing second in both the King Edward VII Stakes at Royal Ascot and the Gordon Stakes at Glorious Goodwood when in the care of John Gosden.
"The cards didn't fall right for him in the second half of last year with the ground being very much on the easy side for his main targets," said Cox.
"This is at the bottom end of his trip preference, but he's in good form and it's a good starting point for him.
"He's a very well-balanced horse and he's a horse that comes out well on the ratings on the day. I'm pleased he's got a nice draw (three) as well."
Autocratic is another who has been absent since August, but connections report the Sir Michael Stoute-trained five-year-old to be ready to return to action.
"Autocratic has done well and Sir Michael has been happy with him. I watched him work on Saturday and he went well," said Chris Richardson, managing director at owners Cheveley Park Stud.
"Unfortunately, he had a slight injury in training last year which meant we had to draw stumps after his run at Windsor in August.
"The Winter Derby is not normally a race we would have runners in, but Sir Michael is the trainer and was keen to target it from when Autocratic had the slight setback - it looks a good starting point.
"The horse tends to carry a bit of extra weight and is quite a burly chap, so there is a chance the race will bring him on."
Stoute also saddles last year's winner Convey, who has an even longer absence to overcome having been out since May.
In contrast, Gabrial has already had two races in 2018, although he is on a losing streak going back to June 2016.
His trainer Richard Fahey said: "Gabrial has been grand since Wolverhampton. It was a non-event for him really as he got left at the start.
"There are not many options and we felt he should take his chance. He has still got to prove he truly stays a mile and a quarter and will have to find a few pounds with some of them.
"The tight mile and a quarter at Lingfield could suit if all goes well for him."
Utmost will attempt to follow up his all-the-way success in the Winter Derby Trial over the course and distance three weeks ago.
The Gosden-trained four-year-old remains unexposed having had just the six starts.
Despite that victory, rider Rab Havlin does not think the track suits the son of Giant's Causeway.
"We've just kept him ticking along. He's done a piece of work and he's pleased us since his last run," he told At The Races.
"He's a horse who probably wouldn't show you too much at home but with every race he's had, he's taken a step forward.
"He liked setting his own fractions (in the Winter Derby Trial). Hopefully there's a good pace or else we can get up the front end.
"The track doesn't really suit him - it is a bit sharp - so it suited me to be on the front end last time, but if there was a gallop I wouldn't mind sitting second or third and have something to aim at."
Select any odd to add a bet