"I fixed it last Sunday," Bell said. "It was really something very simple. It's one of those things sometimes a coach sees you do something that you don't feel yourself doing or see yourself doing. Then you correct it. And as soon as you do, it's like, 'Why wasn't I doing this before?'"
After he allowed a walk and a home run to the only two batters he faced Saturday, Bell spoke the next day with pitching coach Charles Nagy, and the pair looked at video together.
Nagy asked Bell to make a small change, and Sunday they worked on implementing it during a side session.
"Threw five pitches and I was like consistent with it," Bell said. "It's just something that I wasn't aware of. It's just what happens over the course of a season."
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.