It's not unusual for starting pitchers to not be with the rest of the team at various times. They'll fly in a day ahead if they are going to pitch the first game of a three-game series, etc.

What Roger has done is basically expanded that which is part of the reason I doubt he could be traded unless another team was willing to do the same sort of accomodations or he waived that part of his contract for extra money.

As long as he shows up every fifth day and gives you a 1.41 ERA performance, does it really matter how much time he spends with the ballclub the rest of the time?