The NFL is king in the United States, but that does not mean the coronavirus is going to bow before it.

"You have to focus on fitting football inside of this world of coronavirus and don't get caught up in trying to fit coronavirus inside this world," Cleveland Browns center JC Tretter said on Tuesday on a conference call.

"The way coronavirus has kind of changed how every industry is working, you can't expect just to throw football back in and think that the virus is going to kneel down to almighty football."

Elected president of the NFL Players Association just days before the coronavirus pandemic shut down the sports world in March, Tretter is tasked with helping develop a plan for playing the 2020 season while keeping the league's players healthy.

How exactly the league plans to keep its players safe is a big unknown within a sport that involves high levels of physical contact.

"The way this thing passes along is through contact, and that's what we do for a living," Tretter said.

"We interact with each other at the facility, at practice, weight lifting, at the meal room, it is shoulder to shoulder standing by each other, passing things around. So there is a long list of ideas we need to come up with on how to make this environment safe for us. And that's why it's going to be a lot of thinking involved in that."

Earlier in the day, the NFL's chief medical officer, Dr. Allen Sills, said the league fully expects to have positive cases of coronavirus but the key will be identifying it early and preventing the spread. 

"There's no bad idea at this point, and you kind of have to think outside the box," Tretter said. "And just because it's an idea doesn't mean things are definitely going to happen, but you need to explore it, and you need to understand it."

Testing will be paramount in order for the NFL to return, but Tretter acknowledges once the league gives the green light for players to return to their team's facilities and practices to commence there are still risks involved and the chance of contracting the coronavirus is still possible.  

"There's a level of risk to everything," Tretter said. "You're facing a level of risk right now going to the grocery store. There's always going to be a level of exposure that people are going to face in this. So I don't think we'll ever get to a point where there's no risk of exposure. 

"Coming in contact with other people is a risk of exposure. So that's never going to be down to zero. Our job is to try to get that to as close to zero as possible, and that's why you kind of have to look at everything."