"He's my center fielder," Mackanin said before Sunday's series finale against the Giants.
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But Herrera has taken a step back defensively this season, appearing to lose his concentration at times. He has committed seven errors in 74 games compared to five in 136 games last season as a rookie. His Defensive Runs Saved has dropped from 10 to minus-7, according to FanGraphs.
"Go out there and take some fly balls to change your perspective a little bit," Mackanin said about his motivation to have Herrera work in right field. "That's it. There's no plans to move him. If he reads something into it, good. Maybe he'll think that he needs to do better. There's nothing imminent. There's no plans for me to move him out of there."
Todd Zolecki has covered the Phillies since 2003, and for MLB.com since 2009. Read his Phillies blog The Zo Zone, follow him on Twitter and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.