As it plans for what it hopes is a full 2020 season, the NFL has acknowledged the inevitability that a number of its personnel will be infected by the coronavirus. Sustaining the season throughout the fall will require the effective use of testing and isolating procedures currently under development.

"We fully well expect that we will have positive cases that arise," NFL chief medical officer Dr. Allen Sills said. "Because we think that this disease will remain endemic in society, it shouldn't be a surprise that new positive cases arise. Our challenge is to identify them as quickly as possible and prevent spread to any other participants. We're working very diligently on that, and we'll have some detailed plans at a later time."

Sills was among a group of health officials who updated owners Tuesday during a two-hour conference call on the current state of coronavirus planning. He later told reporters that the league is working with the NFL Players Association on more immediate needs, such as a protocol for getting players and coaches back to team facilities.

The NFL allowed teams to reopen their business offices Tuesday, but there has not yet been an agreement on when the full staff can return or whether there will be any on-field activities before the league closes for the summer on June 26.

"We're not putting dates on the calendar at this point, because I'm looking at this as not date-based but science- and technology-based," Sills said, "We feel there are certain important steps that need to occur, with regard to testing, with regard to test availability, with regard to test reliability, and also our continued evolution of understanding of how to manage exposures. All of those things are continuing to evolve. When we and the players' association feel that we are at a point of satisfaction with that science, then we'll be ready to move forward."

Many around the league consider it unlikely that teams will be on the field for minicamps or organized training activities before the start of training camp, which is scheduled for late July. National testing capacity will need to increase significantly by then, because on Tuesday, Sills committed that the NFL will not pull away tests that are needed elsewhere.

"We want to make sure," Sills said, "that we are in no way affecting the supply of tests that are needed in the health care system in any of our markets or around the country at large. That's a strong commitment from all of us."