As the NBA prepares to to resume its regular season this month, a number of league insiders have expressed concern about the long-term health effects for players who test positive for COVID-19—the novel disease that forced the NBA's months-long hiatus.

"There are unknown effects it has on lung capacity, unknown effects it has on cardiac health," an anonymous GM told ESPN"What if a 24-year-old catches it in Orlando and, in 14 days, he quarantines and is fine, but then he has these everlasting heart problems? [Or he] gets winded so easily, or he becomes a little bit too susceptible to fatigue? ... These are all the unknowns."

As with any new virus, there are many questions surrounding the long-term, recurring consequences of COVID-19. Heart failure, brain damage, and lung scarring have all been linked to the potentially fatal virus, which is why every athlete who tests positive for COVID-19 is required to undergo a medical screening before returning to the court. According to ESPN, league officials are primarily concerned about the respiratory issues the virus could cause among infected players, as their intensive physical activity could exacerbate the long-term effects.

"The amount of cardiac damage can increase if you continue to exercise in the face of an active infection," said Matthew Martinez, a consulting cardiologist for NBA. "So you're somebody with a low-grade fever, and you have a little bit of symptoms. And, a week later, you're fine. Do you have cardiac involvement? Now, if you're a regular person, like me, and you're going to go do your [two- to three-mile runs] every day ... that's a different discussion than if you're a professional athlete. So that's the reason why we worry about it that that high level of exercise intensity can increase your risk of having an adverse event when there's cardiac damage related to a virus."

ESPN reports any player who contracts coronavirus will be placed under quarantine for at least two weeks; however, there's a chance they'll have to remain sidelined after the period to fully recover. John DiFiori, the NBA's director of sports medicine, also cautioned athletes to listen to their bodies and avoid over-training during the reconditioning phase.

"The players, the coaches, the medical staff, understand that if a player tests positive, they're going to need time to clear the infection management, they need additional time to recover, and then to begin reconditioning for their sport," DiFiori said. "... If you don't feel well, don't try to push through this. This is not a situation where anyone, whether you're an athlete or not, should try to push through or minimize symptoms or try to ignore symptoms and try to push through to try to continue to work or continue to play a sport."

Twenty-two NBA teams began to arrive in Orlando this week for the 2019-20 season restart. The first game will go down July 30 at Walt Disney World, which reopened Saturday as Florida experiences a coronavirus surge. Dozens of NBA players have tested positive for the disease since the end of last month; however, most of the infected athletes have had asymptomatic or mild cases.