Yeah not sure if it's an actual cba level rule but coaching contracts are prorated, since coaches contracts are guaranteed (unless they agree to a buyout, etc) If Mike becomes a coach for the spurs typically what happens is whatever salary he gets, gets deducted from what the Kings owe him. If the Kings owe him 20 million and Mike signs on to be the spurs coach for 3 years and 15 million then typically the kings would owe him 5 million instead of 20. It's the main reason why you see coaches sit out a season or go into broadcasting or something until their contract is actually up.
Funny enough Mike is a good example of this. He sit out 2 years after getting fired by cleveland the second time, cause he was getting paid by Cleveland (only lasted the one year) AND still getting paid by the lakers (only lasted what, 10 games or something)
