Expecting a busy NBA trade deadline? You might get one, if only because it appears no force known to man can stop the inevitable divorce between Jimmy Butler and the Miami Heat.

But if it doesn’t happen — or if things move slowly than expected, or seem less significant than you might have hoped — you can point the finger at one factor: the increasingly Byzantine trade rules of the new Collective Bargaining Agreement.

The new deal, ratified in the summer of 2023 and now fully in effect after a transition season in 2023-24, dramatically limits the kinds of trades high-spending teams are allowed to make. Teams above the first apron (just over $178 million in player contracts) cannot take on more salary than they send out, among other restrictions. Teams above the second apron (nearly $189 million) have all of those prohibitions, but also can’t aggregate multiple players in a trade. The full details are in this 2023 explainer by The Athletic’s Mike Vorkunov.

Here are the teams most affected by the new CBA. You’ll notice how many of the teams involved in the Butler sweepstakes show up on this list:

Above second apron: Suns, Timberwolves, Celtics, Bucks.

Above first apron: Knicks, Heat, Lakers, Nuggets, 76ers

Within $2 million of first apron: Warriors, Mavericks, Nets

The Athletic’s Fred Katz has more here on how the new rules are likely to impact this year’s trade deadline.