Hellickson tweaked his back while taking a swing in his start Sunday and the team sent him for a precautionary MRI on Wednesday.
"The MRI was more just a peace of mind thing for Ken," Hellickson said, referring to head athletic trainer Ken Crenshaw. "It came back fine."
Because of Monday's off-day, Hellickson will get an extra day of rest between starts.
"I think that's probably what's going to help me make the start," Hellilckson said. "I got to push the bullpen back to today. Monday morning really was the only day I had trouble -- just getting out of bed. I haven't really felt anything since then."
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.