McMahon would be an awesome pickup, but he's a pretty nice prospect already (MLB pipeline has him at #50), so he's going to cost a lot. The Rockies probably aren't going to want a veteran, so getting a third team involved would be the best way to get him. If you start talking big names - Lucroy, Peralta, etc., perhaps that's the way to make some kind of deal. Ultimately, the Rockies want to sign Arrenado to a long term deal, so McMahon would potentially be available. But Colorado would probably want to wait until such a deal is finalized before trading McMahon. Personally I would try to trade some of our younger big league pitching since they will start getting expensive when the next "wave" arrives. If you can fetch McMahon for any of Peralta, Nelson, Jungmann, etc. then I would do it. All of our top players from AA would be here by 2017 and that includes the likes of Houser, Hader, Lopez, and Wagner. Add that to Santana, Braun, Phillips, Arcia, and Reed. Add McMahon to that mix and now we are talking. Beyond these players you have the likes of Davies, Pena and Suter to give depth to the rotation. This is not even mentioning what you can get for Davis, Lind and Lucroy before then. Just my opinion.