One of the priorities of the Washington Nationals this offseason was to ensure that they upgraded their rotation. They appear to have mostly accomplished their goal so far, which makes the possibility of a reunion with Gio Gonzalez unlikely.
Earlier this winter, the Nats were able to sign top free agent starter Patrick Corbin to give the team one of the best 1-2-3 punches in the game. They then followed that up by essentially replacing Tanner Roark with Anibal Sanchez. While many are dubious as to whether this is actually an upgrade, the front office clearly believes so.