Medina Spirit passes the first of three drug tests to race in the Preakness Stakes

Kentucky Derby winner Medina Spirit underwent three rounds of blood-sample testing between May 6 and May 11 — and the first test showed the animal was clear of both prohibited and therapeutic substances, officials said Thursday.

The Bob Baffert-trained horse still needs two more negative results to participate in Saturday’s Preakness Stakes, the second leg of horse racing’s Triple Crown. Race organizers say those results will be available on Friday.

Despite not attending this weekend’s races at the Pimlico Race Course in Baltimore, Maryland, Baffert has three horses set to participate — Medina Spirit and Concert Tour in the Preakness and Beautiful Gift in Friday’s Black Eyed Susan Stakes.

Baffert agreed with race organizers for the horses to be subject to three rounds of out-of-competition blood sample testing. The first blood samples from Concert Tour and Beautiful Gift were also clear of abnormalities, according to a statement from the Maryland Jockey Club.

Medina Spirit, who won the Kentucky Derby two weeks ago in a close finish, is the betting favorite in the 10-horse field.

Baffert was suspended by officials at Churchill Downs in Louisville, Kentucky, after a post-race drug test revealed a therapeutic in Medina Spirit’s system that isn’t allowed to be there on race day.

Officials in Kentucky said a portion of that sample will be retested but results are not expected for weeks.

On Sunday, Baffert revealed the horse had tested positive for elevated levels of betamethasone — an anti-inflammatory corticosteroid sometimes used to relieve joint pain in horses — putting the 3-year-old colt’s Derby win in jeopardy.

Should the positive blood sample be confirmed, second-place finisher Mandaloun will be crowned the winner. The two horses were separated by half a length at the finish line on May 1.

Baffert later provided a lengthy statement on what he said happened regarding Medina Spirit.

“Following the Santa Anita Derby, Medina Spirit developed dermatitis on his hind end. I had him checked out by my veterinarian who recommended the use of an anti-fungal ointment called Otomax. The veterinary recommendation was to apply this ointment daily to give the horse relief, help heal the dermatitis and prevent it from spreading,” part of Baffert’s statement reads.

“While we do not know definitively that this was the source of the alleged 21 picograms found in Medina Spirit’s post-race blood sample, and our investigation is continuing, I have been told by equine pharmacology experts that this could explain the test results. As such, I wanted to be forthright about this fact as soon as I learned of this information,” the statement adds.