Jockey Luis Saez rides Essential Quality to win the Breeders’ Cup Juvenile horse race at Keeneland Race Course in Lexington, Ky., on Nov. 6, 2020. Essential Quality is the first gray horse favored to win the Kentucky Derby in 25 years. Michael Conroy/Associated Press

LOUISVILLE, Ky. — Essential Quality is the 2-1 morning line favorite and will start from the No. 14 post for Saturday’s 147th Kentucky Derby at Churchill Downs.

The $3 million, 1 1/4-mile marquee race for 3-year-colts is back on the first Saturday of May after being delayed to Labor Day weekend last fall because of the coronavirus pandemic. The race is expected to be viewed in-person by 45,000 spectators.

Rock Your World is the 5-1 second choice from the No. 15 slot with Known Agenda the 6-1 third choice despite drawing the rail in the 20-horse field. Hot Rod Charlie drew 8-1 odds as the fourth choice from the No. 9 slot.

The obvious focus in on Essential Quality, the reigning 2-year-old champion who enters the Run for the Roses 5-0. His haul of graded stakes victories includes a gutsy Blue Grass victory at Keeneland on April 3 that vaulted the gray son of Tapit to the top of the Derby standings with 140 points and cemented him as the projected favorite.

He’s one of two entries trained by Brad Cox, who grew up a few blocks from Churchill Downs and is trying to become the first Louisville native to win the race. The Eclipse Award-winner will also saddle Mandaloun from the No. 7 as a 15-1 choice in his Derby debut.

Unbeaten Rock Your World, trained by John Sadler, comes in 3-0 following a 4¼-length victory in the Santa Anita Derby.

Known Agenda leads Todd Pletcher’s four-horse contingent that includes Bourbonic, who drew the outside No. 20 post; Dynamic One (No. 11, 20-1 odds) and Sainthood (No. 5, 50-1). The chestnut colt has won two of three starts this season and has three wins, a second and a third in six career starts.

Hot Rod Charlie’s post draw in the middle brought a loud cheer from his contingent as the colt avoided being bunched inside out of the gate. Trainer Doug O’Neill’s colt won the Louisiana Derby by two lengths and was second to Essential Quality with 110 Derby points.

Essential Quality is also first gray horse to go off as the Kentucky Derby favorite in 25 years. A gray horse hasn’t won the Derby since Giacomo in 2005, and only eight grays have won it since 1930.

According to historians and experts, there are just fewer gray horses compared to more traditional chestnut, bay, brown and black horses, and therefore fewer chances to win the sport’s biggest race. There have been 110 grays running in the Derby over the past 90 years and 7.3% winning it.

THERE IS A MAJOR change coming to the 147th Kentucky Derby. It will be run for the first time this weekend without horses using the anti-bleeding drug Lasix as part of the sport’s plodding attempt to move toward the elimination of race-day medication.

The drug is already widely banned on race days in the rest of the world. Lasix has long been the third-rail in North American racing, with people on both sides of the issue disagreeing about its use.

Formally known as furosemide, it’s given as a $20 injection about four hours before a race to prevent or reduce the severity of exercise-induced bleeding in the lungs. It also works as a diuretic that causes horses to urinate and lose 20 to 30 pounds of fluid, thus increasing their ability to run faster. Humans use Lasix to control blood pressure.

Tracks from New York to California and Maryland to Florida have recently eliminated Lasix on race days after decades of use. This year, the ban extends for the first time to lucrative and prestigious stakes races, including the Derby, Preakness and Belmont.

The goal is a complete elimination of Lasix by July 1, 2022, when the Horseracing Integrity and Safety Act is set to take effect. It will enact national rules on medication and doping that would replace the patchwork that exists in 38 racing jurisdictions around the country.