"I know a couple of years ago he had a really good year for Houston and not so good lately," D-backs manager Kirk Gibson said. "But I think the reports say that he still has a pretty good arm. We're looking for depth for sure."
With the season-ending injury to Patrick Corbin as well as the ineffectiveness of Randall Delgado and Trevor Cahill that prompted the team to remove them from the rotation, the organization's pitching depth has been tested.
To this point, the team has elected not to promote top prospect Archie Bradley.
The Harrell trade comes a couple weeks after the team signed veteran left-hander Randy Wolf and sent him to Reno.
Steve Gilbert is a reporter for MLB.com. Read his blog, Inside the D-backs, and follow him on Twitter @SteveGilbertMLB. This story was not subject to the approval of Major League Baseball or its clubs.