When the NFL starts up, the novel coronavirus pandemic is going to dictate changes. One such change could be the addition of surgical or N95 material to the face masks on players’ helmets.

The NFL and sports equipment company Oakley are testing prototypes, and Thom Mayer, the NFL Players Association’s medical director, said “there will probably be a recommendation” to use modified masks.

The tightfitting N95 respirator mask is the most effective, filtering at least 95 percent of large and small airborne particles, according the Centers for Disease Control and Prevention. A surgical mask is fluid resistant and offers protection against large droplets, splashes or sprays of bodily or other hazardous fluids in addition to protecting others from the wearer’s respiratory emissions, the CDC says.

“Back in early March, I had suggested that we should consider novel and emerging ways to handle the helmets and the face masks and the spread of the virus,” Mayer said on the Adam Schefter Podcast. “And these guys, the bioengineers that we use and that the league uses — Oakley, as you may or may not know, does all the face visors for the league under contract — these guys got the bit between their teeth.”

Protecting players as they participate in a sport in which they cannot help but breathe on and touch one another is not a simple task. Mayer said it’s possible that a player’s entire face mask could be covered. Some of the possibilities are, Mayer admitted, an unusual sight.

“They’ve got some prototypes. They’re doing really good work,” he said. “Some of them, when you first look at them, you think, ‘Gosh, no,’ [because] … you’re just not used to seeing it. But they’re looking at every issue you can imagine, including when it fogs up. What do we do with that? But these guys are used to dealing with this stuff [after designing eyeglasses for use by military members].”

The NFL faces big-picture issues such as state-by-state regulations that complicate matters and a schedule that must allow for possible adjustment, as well as more granular details. Major League Baseball, for instance, has sent a proposal to its players’ union that covers restrictions on actions such as high-fives and spitting.

When you think about all the details of a football game — the number of times players put on and remove helmets, communal hydration sources, huddling and conferring on the sideline to strategize — it’s a daunting prospect. In the NFL and other sports, it will be important to identify players who are at higher risk.

“For a player like that, getting the helmet off, putting a mask on right afterward, maintaining social distancing when not in the field as much as possible, using single-use hydration — whether water, Gatorade, whatever it might be — I mean, just every little detail,” Mayer said. “Anybody who’s got a risk, I would advise them to be zealous, religious and, frankly, almost maniacally committed to minimizing the chance of spreading the virus.”

The NFL began allowing teams to reopen their facilities Tuesday as long as they comply with state and local guidelines and with health and safety protocols previously outlined by the league. Coaches and most players are not permitted to be in the facilities during this initial phase of reopening.

Protocols for teams include temperature checks of employees and visitors, social distancing measures within offices, the use of face coverings and the appointment by each team of an infection control officer. A team can have no more than half of its staff (up to 75 people) in a facility during this phase of reopening.