Diamondbacks manager Bob Melvin has been fired and will be replaced by A.J. Hinch, who was Arizona's VP of Player Development, SI.com has learned.

Hinch, 34, played with the A's, Royals, Tigers and Phillies between 1998 and 2004. He is expected to be introduced at a Friday news conference.

Early speculation had centered on third-base coach Chip Hale or bench coach Kirk Gibson, but general manager Josh Byrnes preferred a non-traditional hire in an attempt to shake things up.

The Diamondbacks are a very disappointing 12-17 this season. Since starting 20-8 last year, they have gone 74-89. Arizona, a talented young team that was looked upon as the biggest threat to the Dodgers in the NL West, has not hit. Another issue may have been D-backs prospects thriving after leaving the team, such as Carlos Quentin, and to a somewhat lesser degree, Emilio Bonifacio.

Under Melvin, the Diamondbacks improved 26 games in 2005 and won a National League-high 90 games in 2007 when they reached the NLCS.

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