They are afraid to play us. Want to save their energy for the Bucks. That's a little tongue in cheek. But only sorta.
If you are the Bucks and you face the Suns and Bucks back to back, you are probably not really confident you are going to win both games. Worst thing to do is beat yourself up against the Suns and then lose to the Bucks too. Might be better to take the loss against the Suns, let your players heal another day, and then go for the win against the Bucks--a conference opponent.
Thinkin out loud here.