But despite a franchise-best 20–8 start in the months of March and April, they couldn't maintain the division lead late in the season and collapsed with many losing streaks and stumbled to an 82–80 record, good enough for a second-place finish, only two games behind the Los Angeles Dodgers.

One of the more shining moments of April was when rookie pitcher Max Scherzer made his major league debut by pitching 4.1 perfect innings of relief, where he struck out 7 Astros.

While doing this, Max passed Pete Richert of the 1962 Dodgers for the record for the number of consecutive batters retired (13) for a pitcher making his MLB debut as a reliever.

[1] Orlando Hudson, one of the more consistent offensive D-backs players in 2008, underwent season-ending surgery on his left wrist August 9 in the wake of a collision with catcher Brian McCann of the Atlanta Braves.

LF Eric Byrnes has been on the 60-day disabled list since late June, with a torn left hamstring, and was not expected to return to the lineup this season.

On August 11, 2008, Dallas Buck, RHP Micah Owings (pending clearing of waivers), and one other prospect were traded to the Reds (in last place in the NL Central at the time) in exchange for OF Adam Dunn.

On August 31, the Diamondbacks acquired former World Series MVP David Eckstein to fill the hole at secondbase which was opened after Orlando Hudson was placed on the disabled list.