NEW YORK -- As the season wears on, managers of opposing clubs continue to approach Terry Collins with the same question: "What happened to Lucas Duda?"

The Mets are still searching for the answer themselves. So strong over the first two and a half months of the season, Duda scuffled around the All-Star break, fell to Triple-A Buffalo and has been stuck there since.

But no longer. Duda will return to the big leagues in time for Sunday's game against the Astros, the team announced Saturday afternoon, with a corresponding move coming in the morning.

He will not be here to sit on the bench. According to Collins, Duda should play most days in left field down the stretch. He will also sub for Ike Davis at first base on occasion, giving Duda plenty of opportunities to position himself for a starting job next spring.

But offensive results are no guarantee. Duda is hitting just .260 in Buffalo with three home runs in 96 at-bats, production comparable to that of his time with the Mets. He entered Saturday's play in a 5-for-23 slump.

"He's had some good games in Buffalo and he's had some games that are similar to what we saw here," Collins said. "But they tell me they thought he's made some improvements, and we're certainly anxious to get him back, because I still think he's a threat in the middle of the lineup."

Duda certainly was for a long stretch, ranking second on the Mets in OPS (.873) from July 10, 2011, until June 24, 2012, behind only David Wright. His 132 hits during that span were also second on the team. His 23 doubles were third. His 21 home runs were first, five more than anyone else in orange and blue.

But Duda struggled mightily from late June until his demotion, leaving the Mets -- and their opposition -- scratching their heads.

"When he gets back here, I want to get him in the lineup," Collins said. "I still think his ceiling is high and I still think he's part of the future."

Lack of patience contributing to offensive woes

NEW YORK -- The root of the Mets' offensive struggles may lie in their approach. Known throughout the early season for their long, grinding at-bats, the Mets have shown precious little of that in recent games. Astros pitchers, for example, needed only 114 pitches to polish off the Mets in Friday's loss. Rockies hurlers needed just 108 pitches on Tuesday to record 27 outs.

It is becoming an out-of-character trend. The Mets drew rave reviews earlier this season for their ability to prolong at-bats, fouling off pitches and knocking out starters in the middle innings of games.

So perhaps it is no surprise that their sudden inability to do that has coincided with their worst offensive stretch of the season. Entering Saturday's play, the Mets had scored two or fewer runs in seven straight games for the first time in 30 years.

"We've still got the guys in the lineup to do it," manager Terry Collins said. "We've just got to -- when we get a ball to hit, we've got to put a swing on it and put it on the barrel and hit it where nobody's standing, and that's what we're not doing."

For evidence that his team still possesses that ability, Collins pointed to the 11-pitch walk that Justin Turner drew in Wednesday's game and the seven-pitch flyout that Ronny Cedeno grinded out to end the game.

"We've had some guys that have had good at-bats," Collins said. "We've seen them this week. Even though we've lost, we've seen some good at-bats this week."

Worth noting

Turner replaced Daniel Murphy in the starting lineup for the second straight game on Saturday, as part of Collins' plan to give Murphy a two-day rest. Murphy should be back in the lineup on Sunday, playing second base.