The Arizona Diamondbacks activated left-hander Doug Slaten from the 15-day disabled list Wednesday and optioned right-hander Billy Buckner to Triple-A Tucson. 

Arizona traded for Adam Dunn to boost its offense. 

If not for their dominance over the Colorado Rockies, the NL West-leading Arizona Diamondbacks would be looking up in the standings. 

Randy Johnson pitched six solid innings and singled in a run, Adam Dunn had a double in his Arizona debut and the Diamondbacks beat the Colorado Rockies 4-2 on Tuesday night. 

Adam Dunn went from the cellar of the NL Central to the top of the West, and he's going to get every opportunity to help the Arizona Diamondbacks secure a spot in the postseason. 

The Arizona Diamondbacks acquired Cincinnati Reds outfielder Adam Dunn in exchange for three prospects Monday, August 11. 

MEDICAL WATCH: 2B Orlando Hudson (wrist) suffered a fractured bone and ligament damage on Aug. 

MEDICAL WATCH: 2B Orlando Hudson (wrist) suffered a fractured bone and ligament damage on Aug. 

Now hitting fourth, right fielder Adam Dunn. 

--OF Adam Dunn will hit cleanup and play right field in his Diamondbacks debut Tuesday in Coors Field. 

Now hitting fourth, right fielder Adam Dunn. 

--OF Adam Dunn will hit cleanup and play right field in his Diamondbacks debut Tuesday in Coors Field. 

Adam Dunn had no idea the Cincinnati Reds were about to trade him to the Arizona Diamondbacks on Monday. 

The Diamondbacks have acquired a big bat for the pennant race. 

Arizona's struggling offense got a very big boost on Monday.