LOUISVILLE, Ky. – The Thursday of racing at Churchill Downs during Derby week – known as Thurby – provides fans with a taste of what the on-track experience is like for the Kentucky Oaks and Kentucky Derby. The day further represents a sampling of the stellar stakes action soon to come. Although no graded races are a part of the 11-race card on Thursday, two six-figure stakes, the $125,000 Unbridled Sidney and $115,000 Opening Verse, highlight the day. Both stakes, scheduled for the turf, are well matched and deep, with the Opening Verse in particular landing an accomplished lineup. Graded winners Hembree, Hot Springs, Monarchs Glen, Ballagh Rocks, and Om are among the 10 horses in the body of the one-mile grass race, and another four horses are on the also-eligible list. “It should be a $300,000 race, probably,” said Mark Casse, who trains Opening Verse entrant First Premio, a 5-1 shot who won the Colonel E.R. Bradley Stakes this winter at Fair Grounds. Although not a graded winner like some of his counterparts, First Premio is one of numerous contenders in the Opening Verse. In addition to his stakes victory in the Bradley, he won an allowance at Keeneland on April 5, his second win from three starts this year. Brian Hernandez Jr., aboard for all three races, rides again Thursday. The Opening Verse marks the U.S. debut of Monarchs Glen, a gelded son of Frankel who previously was based in England with John Gosden. Monarchs Glen is a three-time stakes winner overseas, taking the E.B.F. Stallions Stakes and the Grade 3 Darley Club as a 3-year-old in 2017, as well as the Wolferton last summer as a 4-year-old at Royal Ascot. Hall of Famer Bill Mott, who took over his training for a U.S. campaign, initially entered Monarchs Glen for owner Juddmonte Farm in an April 14 allowance at Keeneland going 1 1/8 miles, but scratched him when the race was moved from turf to a wet main track due to inclement weather. “It might not be ideal, but Bill’s keen to get him started over here and I think running a mile with plenty of speed in the race will at least give him a nice experience to sit behind the pace,” said Garrett O’Rourke, general manager of Juddmonte Farms. Well suited to the mile is Mott’s other entrant, Ballagh Rocks, the tepid morning-line choice at 4-1 odds, who besides winning the Grade 3 Poker in 2017 has also placed in three Grade 1 races at the distance. The Opening Verse, the eighth race Thursday, will be followed by the Unbridled Sidney, the 10th on the afternoon. A 5 1/2-furlong grass sprint, the race attracted the top four finishers from the Giant’s Causeway at Keeneland on Apr. 13, a race Morticia won by a neck over Excessivespending. Morticia was second in the Unbridled Sidney last year, leading for much of the race before being caught in the closing strides by Triple Chelsea. Besides the group from the Giant’s Causeway, the Unbridled Sidney offers a mix of invaders from other regions of the country, including California shippers Painting Corners, Lady Suebee, and Spy Ring. The race is also the comeback spot for Ruby Notion, who won the Grade 3 Kentucky Downs Ladies Sprint last September before a fourth-place finish over yielding ground in the Grade 1 Breeders’ Cup Turf Sprint at Churchill Nov. 2. There is the potential for wet turf again due to a threat of showers in the long-range forecast for Thursday.