Myocarditis, a rare heart condition linked to the coronavirus, should concern the NFL as it aims to begin a season during the pandemic, according to the Baltimore Ravens’ head physician.

Dr. Andrew Tucker said evidence suggests COVID-19 can increase the risk of inflammation of the heart, which can lead to myocarditis and cause sudden cardiac arrest. Speaking to reporters Wednesday on a video conference call, Tucker said even a chiseled football star who contracted the coronavirus would have some chance of developing the condition.

“The risk is low,” Tucker said. “But how low is a little bit premature to say because we just don’t have the data. This hasn’t been going on that long.”

Reports indicated the threat of heart inflammation played a role in the Big Ten and Pac-12 conferences announcing the cancellation of their fall sports seasons earlier this week. The Athletic’s Nicole Auerbach wrote that the Big Ten knew of at least 10 players diagnosed with myocarditis before making an announcement.

In a document meant to guide the Pac-12′s path through the coronavirus crisis, a medical advisory board warned of “new and evolving information regarding potential serious cardiac side effects in athletes.”

Tucker said doctors noticed the prevalence of myocarditis in COVID-19 patients during the early stages of the pandemic, and NFL medical personnel are cognizant of the connection.

“It’s a concern,” said Tucker, a former president of the NFL Physicians’ Society. “Myocarditis is one of the rare causes of sudden cardiac arrest in our athletes and it is usually caused by a virus that causes inflammation in the heart. It is very rare, fortunately, but it can happen and it can happen theoretically with any virus, but certain viruses tend to make it more likely. Unfortunately, COVID has proven early on to be a virus that tends to involve the heart.”

Tucker said any NFL player exposed to the coronavirus or who tests positive must undergo cardiac tests before returning to regular team activities. If a player’s test leaves doctors with any concerns or if a player reports symptoms of heart inflammation, that player would meet with a specialist for more evaluation, according to Tucker.

Still, much remains unknown about COVID-19 and the damage it can cause to a person’s health.

Players began reporting to NFL training camps last month, and the Ravens plan to hold their first padded practice Monday. Their regular-season schedule is scheduled to begin Sept. 10.

To Tucker, the most pressing question about the coronavirus’ link to myocarditis is whether COVID-19 patients who do not experience strong symptoms have a heightened probability of developing a heart condition.

“We understand that people that are very sick with COVID have probably a significant percentage of risk for myocarditis,” he said. ” What we are sorting through and gaining more knowledge about, is people who have just been exposed to the virus and have no symptoms or have minimal symptoms. We are learning every week whether any of those people have increased risk of heart troubles.”

Tucker said medical experts believe cardiac tests performed about 10 day after a coronavirus diagnosis should uncover any possible heart inflammation in a patient. But as doctors continue to learn about the disease, they could adjust that perception, Tucker said.

As of now, NFL protocols do not necessitate follow-up evaluations on players who recover from the coronavirus and show no signs of heart inflammation on their initial tests. Tucker said it’s valid to question whether it might be wise to re-examine players deeper into the future to ensure they don’t develop a heart condition.

“Do you retest players at four weeks or six weeks or eight weeks?” Tucker asked. “Those are not part of the protocol right now. But as our knowledge base grows over time, it could change.”

On a 40-minute call with reporters Wednesday, Tucker marveled at how the NFL and its players association developed guidelines for a return to work. He said the Ravens have established strict protocols to aim to avoid a coronavirus outbreak, and teams across the league are testing players daily and promoting an array of safety measures.

“You’d be amazed and impressed to the extent that these clubs are invested in this,” Tucker said.

Even so, myocarditis’ link to the coronavirus has drawn the attention of medical experts and the football world. The NFL is taking such risks seriously, according to Tucker.

“From Day 1, the protocols have been very conservative with the heart,” he said. “Certainly in the case of the NFL, and all the major leagues and colleges are sorting through these: What’s the right thing to do for athletes returning after potential COVID exposure?”