What happened: A three-team concept would bring a four-time NBA champion to the Boston Celtics through a traded-player exception. Boston would send out a player under contract for three more seasons.

Why it matters: The exception provides a route to add salary while Boston operates under the first-apron hard cap. Any transaction would require all three clubs to accept the proposed salary routing.

What to watch: Watch for the framework to progress from an outside proposal to substantive team talks.