$11m is not that great for an AS budget. Most likely, the projections you see are not going to be that accurate.
The development of P2 from S13 to S14 has slowed down considerably. 97 is not going to be attainable. And his vsL rating has not moved in the current season through two development cycles, so 74 is probably out of reach as well.
Back to your original question . . . he is a major league pitcher right now. I see no point in holding him back for further development in the minors because I don't think he's going to get much more. He can keep developing at the major league level as long as he's in the rotation and getting regular work.
The only reason why you might want to hold him back would be to delay his arb clock. I guess it depends on what your long-term expectations are for your team.