The NBA is estimating that there would be "significant financial turmoil" if the season competed with the Summer Olympics for television ratings, sources told Adrian Wojnarowski of ESPN.
A potential mid-January start would take the season into July, thereby competing with the Olympics. A January start could also cost the league up to $1 billion in revenue.
The league would also then have to readjust the 2020-21 schedule, according the sources.
The NBA prefers a December 22nd start date, while the NBPA have pushed for mid-January to begin the season.
Negotiations will continue through the weekend and into next week.