Diamondbacks GM Kevin Towers acknowledged Wednesday that he's open to trading a shortstop. Didi Gregorius and Chris Owings are currently battling over starting duties in Diamondbacks camp. The loser of that competition could be shipped to another team before Opening Day. "For us, it would have to be the right deal," Towers told the Arizona Republic. "Our biggest needs in our system are catching. If it's the right, top-notch catching prospect. Someone we could have right behind [Miguel Montero]. More of an upper-level guy. Maybe a top, upper-end starter. We have a lot of bullpen depth, infielders. Maybe an outfielder, but probably more catching and Double-A, Triple-A type starter."