NFL Players Association medical director Thom Mayer said he's optimistic the 2020 season will take place but that the union and the NFL will know a lot more in late May or early June about whether playing this season is viable.

Mayer discussed the coronavirus pandemic and its impact on the NFL during an appearance Monday on a podcast hosted by ESPN's Adam Schefter.

Mayer said the NFLPA has created a COVID-19 brain trust that includes members from Harvard, Duke, Johns Hopkins, the CDC, the White House, the state department and the office of Dr. Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases. The union has consulted with that group twice, and the first consultation led to the shutdown of team facilities last week.

Mayer noted every NFL team, with the exception of the Green Bay Packers, is located near a coronavirus hotspot; he believes it won't be until late May or early June when those hot spots begin to open up. The timing means organized team activities are unlikely this year and a return with training camp is the likeliest scenario. The NFLPA would agree to the reopening of facilities only after consulting with its COVID-19 brain trust.

"So OTAs, probably not going to happen. As you know, the clubs are closed for now and will remain closed for a while. But I'm very optimistic," Mayer said. "You know, you look at somebody like Drew Brees and [wife] Brittany Brees gave five million dollars to New Orleans. And you may have heard Drew the other day say, 'Hang in there, hang tough.' And that's what we have to do. We have to hang in there and hang tough -- but we have to scenario plan for disasters in terms of the way we did it at 9/11."

Mayer pointed out he was the command physician at the Pentagon on 9/11, so he has experience with disaster planning.