Duda is batting just .190 (19 for 100) with four extra-base hits in his past 29 games. New York's starting right fielder entering the season, Duda is batting .241 with 12 home runs and 44 RBIs this year.
"He's gotta find that stroke he had when he first got here. He's been playing out of position a little bit. He's done an absolutely great job," manager Terry Collins said. "But he's here to hit, and when he's not hitting, we gotta get it fixed."
Duda's defense in right has been subpar as well, which contributed to the decision to send him down. Collins said the organization plans to move Duda back to his normal positions -- first base and left field -- while he's in the minors.
"To be honest, I told him we're gonna put you back where you're comfortable," Collins said. "Let's see if he can concentrate more on his offense, because that's what's gonna get him back here."
Collins would've loved if Duda could've fixed his swing in the majors, but the Mets are struggling, having lost 10 of their past 11 games, and the manager couldn't afford to have another hole in the lineup.
"I gotta find some offense," Collins said.
"We gotta go with the hot hand right now," Collins said.
Prior to Tuesday's game against the Washington Nationals, the Mets also activated rookie right-hander Matt Harvey from the taxi squad, promoted reliever Manny Acosta from Buffalo and demoted reliever Pedro Beato to the Bisons.
Acosta will be available on Tuesday night after throwing 21 pitches during a scoreless two-inning outing for Triple-A Buffalo on Monday night, Collins said.
Shortstop Ruben Tejada, injured on Monday night when Roger Bernadina slid into his right shin, will get the night off, Collins said. Tejada, who did not require stitches, told Collins he's fine and would be available to play.
Closer Frank Francisco (right knee) received an injection after being unable to begin a rehab assignment Monday night because of discomfort. Francisco said the injection helped him, and the Mets announced Tuesday night Francisco will begin his rehab Wednesday with Double-A Binghamton.
"We need him back very badly. Our bullpen has had a tough time," Collins said. "We have bullpen help. It's in-house. We just gotta get him back there. The reason he got the injection was to get him done so that this thing doesn't get done and flair up again. He's already been out a month, so what's two more days?
"I would think in the next 5-6 days Frank will be in our clubhouse."
Mike Mazzeo is a contributor to ESPNNewYork.com.