In any other year, N.F.L. facilities across the country would be buzzing this week, when teams are allowed to begin their off-season workout programs, the first organized football activities since they ended the prior season.

Normally, this is a time when teammates are reunited for workouts and position meetings. Coaches get their first in-person look at free-agent signees, and trainers assess how injured players are recovering.

But like nearly all other nonessential businesses in the country, N.F.L. teams are in lockdown, with all coaches, players and staff working from home. This has thrown one of the most critical stretches of the league’s calendar into flux, and forced the N.F.L. and its players’ union to develop a host of rules changes. Teams have scrambled to adapt to working from home, and the coronavirus advisories have put the N.F.L. at the mercy of government and health officials.

Unlike other pro sports leagues, whose seasons were fractured by the pandemic, the N.F.L., despite the turmoil, has had an easier time so far. Its first game isn’t until Sept. 10. Still, the league and the N.F.L. Players Association had to create one set of guidelines for 32 teams, 2,000 players and hundreds of coaches, trainers and other staff.