"It turns out to be a numbers game. If you have 2 to 3 percent of the population infected at any one time, and then you bring together the hundreds of people needed for a football game, you're going to have several people in that group likely to be infected," said Dr. Larry Chang, an infectious disease specialist at Johns Hopkins Medicine. "I think the experience of baseball just reflects what's happening in our communities, which is that there is a very high amount of community-wide transmission. So if this level of transmission isn't dramatically decreased, I'm pretty skeptical that there's going to be an uninterrupted football season."
Ravens president Dick Cass, who has coordinated the team's pandemic response, said that despite such concerns, a bubble would have been nearly impossible for the NFL given its numbers and the six-month duration of a full season.
"Obviously, it's not as good as a bubble," he said. "But when you think about 32 teams and trying to play all your games in a few areas, I don't think it was practical."
NFL teams are testing players and staff members daily, with those who test positive and display symptoms required to sit out for at least 10 days. Players and staff members are also wearing tracking devices that will allow teams to isolate those who've come into close contact with an infected person. At the Ravens' training complex in Owings Mills, glass partitions separate lockers, players wear masks everywhere except on the field and meals are consumed one person to a table in the team cafeteria.
But those measures won't prevent anyone from contracting the virus away from team facilities.
"Can we on the staff and can our players take care of ourselves when we leave the building?" Cass said when asked to name his greatest source of anxiety. "We're going to have to change what we normally like to do. ... It's really going to change people's conduct, and if it doesn't, we're likely to have an outbreak."
A player or coach who tests negative on Friday could still conceivably enter a Sunday game with the virus and spread it to teammates and opponents. What would happen if a team saw an entire position group sidelined by COVID-19? Or if an irreplaceable player such as Jackson contracted the virus shortly before a playoff game? Questions like these have already scrambled the baseball season.
"Yes, you're seeing this stuff," Ravens running back Mark Ingram II said when asked if MLB's difficulties have increased his anxiety. "There are cases, but you just try to stay positive. We try to stay with the protocols that our team has set for us in the facility. When you leave the facility, just try to be as safe as possible. Stay at home and taking on the necessary precautions to make sure that you're not exposing yourself unnecessarily to anything. ... We're trying to stay positive and stay hopeful."
It was hard to miss the uneasiness in linebacker Matthew Judon's words as he prepared for the start of camp. "I really don't know. We don't know," he said. "There's so much unknown and so much uncertainty that's going on right now. We've really got to try, got to jump in and see how it goes. But I don't want anybody to get sick of this or anybody to take this back to their home. So it's kind of crazy, but we're going to try."
Cass said it's too early to draw specific lessons from baseball's experiences, but he said the NFL would benefit from the relatively tight travel windows required for once-a-week play. Nonetheless, he won't be surprised if the league faces outbreaks and schedule interruptions.