The New York Racing Association, determined to have the final word on who is allowed to compete on its racetracks, charged the embattled trainer Bob Baffert on Friday with “conduct that is detrimental” to the sport and “potentially injurious” to both horses and riders.

At the same time, the association established a hearing process that it said would allow trainers, jockeys and owners to receive due process.

Baffert was suspended in May from Saratoga Race Course, Belmont Park and Aqueduct Racetrack after his colt Medina Spirit, the winner of the Kentucky Derby, failed a post-race drug test at Churchill Downs.

But Judge Carol Bagley Amon of the U.S. District Court for the Eastern District of New York overturned the suspension, ruling that Baffert had not been offered the opportunity to respond to allegations made against him.

Amon said that a prompt post-suspension hearing, where Baffert could have rebutted any claims against him, was required under the Constitution. But she said the racing association “had held no hearing — let alone a prompt one.”

David O’Rourke, president and chief executive of the association, said the new hearing rules and procedures would meet the requirements of due process in the cases of Baffert and Marcus J. Vitali, a trainer facing a similar charge.

“NYRA has a responsibility to protect the integrity of the sport of thoroughbred racing,” O’Rourke said.

Lawyers for Baffert were not immediately available for comment.

Medina Spirit crossed the finish line first in the Derby on May 1, only to flunk a post-race test for a prohibited corticosteroid. The result of what is known as America’s greatest horse race has since been contested in state and federal courts.

Lawyers for Baffert have asked for and been granted additional testing of the Derby sample. They hope to bolster their argument that the betamethasone found in Medina Spirit came from an ointment to treat a skin condition, not an injection to improve the colt’s performance.

Last month, the Baffert-trained Gamine won the $500,000 Ballerina Stakes at Saratoga. Gamine is considered the fastest filly in the world; her lone defeat in 10 starts was a third-place finish in last year’s Kentucky Oaks.

Gamine was disqualified, however, after testing positive for the same drug that has put Medina Spirit’s Derby victory in limbo. The two violations were among five Baffert racked up in 13 months.

Still, a possible Derby disqualification is months away and destined to be tied up in the courts for years. First, Kentucky racing officials will conduct a hearing and issue a ruling. If they disqualify Medina Spirit and either suspend or fine Baffert, he could appeal to the full state commission. If the unfavorable ruling is still not overturned, he could pursue a remedy in civil court.

In 1968, the Derby victory by Dancer’s Image was rescinded after a drug test showed the presence of a banned anti-inflammatory drug. It took four years before the horse was irrevocably disqualified.

O. Peter Sherwood, a retired New York Supreme Court justice, will hear NYRA’s case against Baffert on Sept. 27.

Vitali, another trainer, faces similar charges and will have a hearing on Sept. 30 before Robert S. Smith, a retired judge of the New York Court of Appeals.

In the past five years, Vitali was “denied entry, ejected and/or had license applications denied by regulators of thoroughbred racing in Florida, Pennsylvania, West Virginia, New York and Delaware,” according to the charges, “and was sanctioned by the Jockey Club for violating a racing statute, rule or regulation relating to prohibited or restricted drugs, medications or substances seven times in a single year.”