He'll play the march masters tournaments because he'll be required to and if he proves to himself that he's capable of playing good tennis in February then he'll also want to (he is a champion of the game who won't run away from properly returning to the tour's diverse surfaces once he's able to return to competition).
Yeah I can't see him skipping both. One maybe but not both. He'd not have an excuse if he plays Acapulco, and then a scheduled exo in New York straight after. Also if he skips both he has a month out of competition and as a general rule he likes to play matches to find form - won't want such a massive break before Monte Carlo I don't think.
Could see him play IW and skip Miami though depending on how IW goes. Both those Masters have a days rest in between matches anyway and suit his game so I think he'll play as long as knee was okay on clay before hand.