Joe Saunders is the weakest link in the D-backs' rotation. Trevor Bauer is the strongest prospect we've had since Justin Upton. Since the only way Bauer is getting his chance is by injury, lack of production, or trade; trade is the most likely.
This article states that Baltimore is looking for starting pitching and are willing to trade. Since our orginizations have recently swapped players, Hernandez for Reynolds and others, this could be an easy deal. They have some nice infielder prospects as well as some pitchers we could use.
The dbacks would also want to trade Saunders somewhere he would want to go as a 'no hard feelings' gesture. Considering he is from Virginia which is right next door and the Orioles are in good shape so far this season, I don't see why Joe wouldn't be happy with it too.