TOKYO – In his previous job, Dr. Jonathan Finnoff ran the Mayo Clinic Sports Medicine Center in downtown Minneapolis and consulted for the Timberwolves and Lynx. He lived in the Linden Hills area, his neighborhood "Rockwellian."

"We loved it," he said.

He left Mayo in January 2020 for his dream job and daunting circumstances, becoming chief medical officer of the United States Olympic & Paralympic Committee on the cusp of a pandemic that would postpone the 2020 Games.

On Friday, after participating in a USOPC news conference, he stood backstage, waxed nostalgic about Minneapolis and explained how he tried to educate American athletes, even those believing conspiracy theories, about vaccinations.

"Vaccination status is actually a very contentious issue in the United States, which is unfortunate, because if we look at it from a medical and scientific aspect, these are very, very safe vaccines," he said.

"While they went through the process rapidly, they did not cut corners and [the shots] are extremely effective.

"So if we wanted the pandemic to end as we know it today, we could be a huge world player in that."

His tutorials began at home. He acknowledged that while the USOPC doesn't require athletes to be vaccinated, he has spent copious time trying to explain why shots should go into even well-toned arms.

"It's been a real challenge," he said. "I've tried to use evidence, logic and common sense to dispel misinformation, and then also reduce barriers. How do you sign up? We have health-care navigators that would help people, and do it for them. We would identify locations near them, wherever they are in the country.

"We did webinars, offered written information, did sessions one-on-one with athletes who had specific questions, but also with teams. So we tried to provide as much education and reduce any barriers that we could."

Barriers remain.

On Friday, hours before the Opening Ceremony, Olympic organizers announced their highest daily total of positive COVID cases: 19, including three athletes.

Some high-profile American athletes, including tennis star Coco Gauff and top golfer Bryson DeChambeau, had to withdraw from the Olympics after testing positive for COVID. They did not say whether they were vaccinated, but basketball player Katie Lou Samuelson said she was fully vaccinated when she tested positive before the games.

U.S. officials said that 83% of their athletes are vaccinated, a total is based on self-reporting.

Michael Andrew, a member of the USA swim team who was born in Edina, has refused to get vaccinated, using the word "freedoms" while explaining his decision. Among USA athletes, wrestler Kyle Snyder, gymnast Leeanne Wong and runner Cole Hocker said they did not get vaccinated.

Maya DiRado, who won four medals in swimming in Rio in 2016, last week launched a Twitter thread expressing her disappointment in Andrew's stance, writing that he should be proud to receive American-made vaccines and asking, "Are we helping to stop the pandemic that is continuing to wrench loved ones from their families in both our home country and the country that's hosting us?"

Andrew has said in interviews that he didn't want potential side effects from vaccines hampering his training.

The International Olympic Committee encouraged and tried to facilitate vaccinations but did not require them for athletes.

The IOC told Forbes in an e-mail that more than 85% of Olympic competitors have been vaccinated.

In Japan, vaccination rates were close to zero just a few months ago.

Now, less than 20% of the population has received one shot, and less than 10% has received two shots. On Thursday, Japan had 1,979 cases, up about 600 from each of the previous two Thursdays.

Earlier last week, Toshiro Muto, head of the Tokyo 2020 organizing committee, said that canceling the Games remained a possibility, as COVID cases in Japan began to rise and a number of athletes either tested positive or were forced to quarantine because of contact tracing.

With national pride, athletes' dreams and billions of dollars at stake, why are the Olympics (and the USOC) allowing unvaccinated athletes to travel to Tokyo and participate? "It's a personal choice," Finnoff said.

The IOC's position has been that while it wants athletes to be vaccinated, it didn't want to impose any rules that could disproportionately hamper poorer countries, or countries that did not have equal access to vaccines.

For most American athletes, getting vaccinated is a choice, and Finnoff has encountered athletes who feel invulnerable or who believe anti-vaccination propaganda.

"I know God's in control," USA wrestler Snyder said in April. "I'm not worried about it."

Finnoff worries. He became a doctor because, as a student at the University of Colorado studying accounting, he was biking home after an exam and encountered a man who had shot himself. Finnoff hated feeling helpless.

Now he sees his work as trying to help those willing to help themselves.

"Some individuals say, 'My sport puts me at a higher risk for injury, catastrophic injury, than COVID does, where most likely I'm going to be either asymptomatic or have mild symptoms because I'm young and healthy,' " Finnoff said. "The difference between putting yourself at risk in a sport, and putting those around you at risk in a pandemic, is what I really try to emphasize.

"If you will not do this for you, because you don't think it will impact you, then think about your parents, your coaches, your teammates, friends and loved ones. The impact is far broader than just ourselves.''