I'm pretty sure Barrett was going to the Cubs all along in that trade, just that the A's had something that Montreal wanted and the Cubs had something the A's wanted, so it was just a roundabout way to get Barrett, IIRC Right, Barrett was an Athletic for a matter of hours. For all practical purposes the Cubs traded Demian Miller for Barrett. Officially they may have been two separate trades with minor leaguers and/or PTBNL involved, but I think Miller for Barrett was the gist of it.