Dr. Anthony Fauci, the nation’s leading infectious disease expert, said its possible NFL fans in Philadelphia and elsewhere will be able to watch games from the stands come September, depending on the course of the virus. But even in the best-case scenario, it probably won’t look like the packed stadiums we’re used to seeing on NFL Sundays.

“If the virus is so low that even in the general community the risk is low, then I could see filling a third of the stadium or half the stadium so people could be six feet apart,” Fauci said in an interview with NBC Sports’ Peter King. “I mean, that’s something that is again feasible depending on the level of infection. I keep getting back to that: It’s going to depend.”

A lot will depend on the level of testing in place by September, especially when it comes to players. Fauci said there’s no guarantee NFL games will even return in front of empty stadiums, and ideally the league would test all players before each game and sideline those who are infected. Because COVID-19 is a respiratory virus, it won’t spread through players’ sweat, but Fauci said the close contact required by the game itself will create prime conditions for spreading coronavirus.

“I would think that if there is an infected football player on the field — a middle linebacker, a tackle, whoever it is it — as soon as they hit the next guy, the chances are that they will be shedding virus all over that person,” Fauci said. "To be 100% sure, you’ve got to test every day. But that’s not practical and that’s never going to happen. But you can diminish dramatically by testing everybody Saturday night, Sunday morning, and say OK, only negative players play.”

Fauci is scheduled to testify before a Senate committee Tuesday but will appear remotely after having come in contact with a White House employee who tested positive for coronavirus.

“I was exposed to that person. So I immediately got tested. I am negative. So, I’m negative yesterday. I don’t know if I’m going to be negative Monday. Understand? It’s almost an impossible situation,” Fauci said.

The Eagles are scheduled to open the season on the road against the Washington Redskins on Sunday, Sept. 13. The Birds’ home opener at Lincoln Financial Field is set for Week 2 against the Los Angeles Rams on Sept. 20.