Hill has slipped from two years ago, when he had a career year, and is batting .251 with eight homers and 49 RBI. Prado's numbers are comparable (four homers, 37 RBI, .274), but Arizona views him as a key asset because of his leadership abilities and versatility.
The two players have similar contracts, with Hill due about $28 million through 2016, and Prado $26 million.
The Diamondbacks have already made two trades but seem reluctant to trade from its core, not only untouchable Paul Goldschmidt but also shortstop Chris Owings, catcher Miguel Montero and pitcher Wade Miley. Prado is close to that category, as well, it seems.