The NBA has had several weeks of "clandestine collective bargaining" discussions with the players' union.

The NBA and its union has until Dec. 15 to give official notification that they plan to opt out of the current 10-year collective bargaining agreement in 2017 and clear the way for a possible work stoppage. 

The NBA and players have broken down into several groups and committees to discuss multiple areas of the CBA.

Both sides have tried to keep discussions private.