The NFL and the NFLPA agreed to final terms on the addendum to the 2020 Collective Bargaining Agreement, the chief hang-up being determining the date by which players would be required to formally opt out of participating in the 2020 season in order to qualify for a stipend.
The language of the original agreement stated that the deadline would be seven days from the time that the deal was finalized, but the deal had not been finalized until last night, so it remained open indefinitely—at this point, 11 days. The new language states that the deadline is Thursday at 4PM.