QUEPOS, Costa Rica — The doctor whose team treated the son of former New York Yankee Brett Gardner at a high-end resort revealed that medics fought frantically to save the 14-year-old boy’s life — but could not revive him.

Dr. Kevin Gannon, who runs Manuel Antonio Urgent Care near the high-end resort where Miller Gardner died, told The New York Post that the teen was unresponsive when doctors arrived on Friday morning, as he raised questions about what may have caused the boy’s sudden death. 

“From what we encountered there, we could not verify a cause of death,” Gannon said.

Brett and Jessica Gardner were on vacation with their sons, Miller and Hunter, when Miller tragically died.

“To us it was very confusing.”

“We responded to a minor without vitals,” he added.

“We tested him for cardiac arrest and performed CPR for more than 30 minutes. There was not really much we could significantly do.”

Gannon, who said his staff had not treated Miller before being called to the resort Friday, added that the Gardners had all vomited after getting sick following the dinner the night before.

But, he said he did not believe that either food poisoning or an allergic reaction were responsible for Miller’s death.

“Some people are saying it was anaphylactic shock from food he ate. But I will say it is very, very rare for a patient to eat food and go that long without a reaction,” Gannon said.

Miller Gardner was staying at the upscale Arenas Del Mar Beachfront & Rainforest resort when he fell seriously ill along with several members of his family, local officials told Inside Edition. Instagram / Hampton Abernathy

“Usually it’s right away.”

He added that he was speaking generally about food allergies and he didn’t know exactly what happened before his staff arrived.

Authorities are still awaiting the results of tests to confirm whether Miller had any kind of allergic reaction.

Brett and Jessica Gardner and their two sons were vacationing at the Arenas Del Mar Beachfront & Rainforest Resort at Manuel Antonio National Park when Miller was reportedly treated by hotel doctors for food poisoning, according to Costa Rican police.

Police initially believed the teen died from asphyxiation due to food poisoning, but ruled out that he choked to death after an initial examination over the weekend.

On Wednesday, authorities said they suspected Miller may have had an allergic reaction to the medication he was given – but Gannon called that unlikely as well.

Gannon said the Gardners had all vomited after getting sick following the dinner the night before Quepos Urgent Care

“Allergic reactions to normal gastrointestinal medications are very rare,” he said.

“Most of the acute GI conditions can be treated with over the counter medication. And most do not have severe side effects or else they would not be over the counter.”

Gannon said he is eager for toxicology tests to be done on the teen — though officials warn that could take months.

Brett Gardner, 41, was an outfielder with the New York Yankees for his entire 14-year baseball career, and was a member of the team’s 2009 World Series championship team.