The Diamondbacks fired former 2007 Manger of the Year Bob Melvin and are expected to replace him with A.J. Hinch, who is the club’s vice president of player development.

The 47-year-old Melvin’s firing comes after a disappointing start by the Diamondbacks, who entered Thursday 8½ games behind the Los Angeles Dodgers in the NL West. Melvin, who went 337-340 in four-plus seasons, had one year left on a contract he received after being the 2007 NL Manager of the Year.

Melvin’s stock rose when he guided a youthful but talented group to the NL West title two years ago. He was dismissed because many of the same players have failed to live up to expectations based on that season, when the Diamondbacks posted an NL-best 90-72 record despite being outscored by 20 runs across the season.

Speculation about Melvin’s future grew with every 1-2-3 inning by the Diamondbacks’ hitters. Arizona entered Thursday with a .225 batting average, by far the worst in baseball.

Arizona’s offense was a major question mark coming into the season, but as long as the pitching came through the D’Backs were expected to compete in a weak NL West. But Brandon Webb’s shoulder injury (and subsequent trip to the DL) was a crushing blow to the club’s starting pitching and the offense has been even worse than expected.

Melvin can’t do anything about Webb’s injury, Conor Jackson hitting .191 or Eric Byrnes averaging a paltry .139. But the reason he was inevitably fired is because the club has lost all emotion. It’s only May and the D’Backs are playing like it’s August and they’re 15 games out of first. Maybe the 34-year old Hinch can breathe some life into a club that certainly has talent, but is currently lacking any kind of desire.