"If he's going to be the everyday first baseman, he's got to start getting in against lefties," Collins said.
Duda entered Saturday 1-for-11 (.091) with five strikeouts against left-handers this season. He has hit .219 against lefties with seven homers in 319 at-bats in his career and .257 against right-handers with 41 homers in 864 at-bats.
"Two years ago, three years ago, when he was playing every day, he faced lefties," Collins said. "He hit them as well as anybody. I think he hit about .275 because he hit the ball to left-center field, wasn't worried about pulling. That's what we've been stressing here the last few days, since he's taken over as the first baseman, is if you're going to play aginst lefties, you got to go back and be that same guy you were before. Don't worry about hitting the ball in the seats necessarily unless you get the pitch to do it. Otherwise, do damage in the other field."
Jack Etkin is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.