© 2014 MLB Advanced Media, L.P. All rights reserved.

8/5/2014 8:31 P.M. ET

Collins gives Duda a start facing lefty Gio

WASHINGTON -- Gio Gonzalez throws left-handed. Lucas Duda swings left-handed.

In the past, that would have been enough for Mets manager Terry Collins to keep Duda confined to the bench for Tuesday's series opener against the Nationals. But with Duda hitting as well as he ever has over the past two months, Collins has committed himself to giving Duda more chances against same-sided pitchers.

Gonzalez, a Nationals starter with a checkered history against the Mets, seemed like a good opportunity.

"Our lefties have hit Gio in the past," Collins said. "I just thought this would be a good test for Lucas to see how he would approach him. Gio's a great pitcher, but we've been talking about giving him that opportunity."

For the most part, Duda's breakout season has not included much success against lefties (a .472 OPS in 69 plate appearances entering Tuesday's play). But the Mets don't know how much of that has been due to an inability to hit them, and how much due to a lack of regular opportunities.

Collins intends to find out by picking and choosing his spots. He is certainly skeptical, understanding that Duda's swing has become more pull-centric since he first came into the league four years ago. But the manager also knows Duda must show growth in this area if he is to remain the team's unquestioned starting first baseman for years.

"If you're going to have him hit in the middle of the lineup, he's got to hit lefties," Collins said. "You can't have a hole there."

Nieuwenhuis hopes to stick with Mets this time

WASHINGTON -- Four times already this season, the call has come. Four times, Kirk Nieuwenhuis has boarded a plane, maybe waited out a layover somewhere, then joined the Mets' active roster.

The first three times, the Mets sent him right back down to Triple-A Las Vegas. This time, Nieuwenhuis hopes to stick.

"You try and keep it on as much of an even keel as possible," said Nieuwenhuis, who took Bobby Abreu's roster spot. "I think one thing that's really been more evident to me this year is that it kind of builds character. I think you can really take some good stuff out of it. You really learn that you can only control how you play. You learn that it's a business in baseball."

Shuttling back and forth between the Minors and the big leagues so often, Nieuwenhuis said, has taught him to be honest with himself. The Mets demoted him each time for a reason; some perhaps more political than others, but the fact is Nieuwenhuis posted just a .246 average and a .328 on-base percentage in his first three Major League stints. What he offered in power, he lacked in consistency.

The outfielder's latest trip to the big leagues involved a red-eye flight and one hour of sleep, all for the opportunity to sit on the bench for Tuesday's series opener in Washington. But Nieuwenhuis understands the drill. In addition to his four big league stints this season, he shuttled back and forth twice last season and once in 2012. As a result, he says he's "as used to it as he can be."

So Nieuwenhuis will ride the bench against lefties, start sporadically against right-handers and hope that what he brings to the table -- respectable power and defense -- will help keep him in the big leagues for good.

"It's going to be day to day right now," manager Terry Collins said, "but for sure, we're going to try to get him some more playing time."

Worth noting

• Outfielder Curtis Granderson received his first day off Tuesday since June 23, when he was ill. With Granderson on the bench, the Mets batted fellow outfielder Juan Lagares leadoff for the first time in more than two full months.

• Closer Jenrry Mejia was "fine" Tuesday, according to Collins, a day after tweaking his back in a non-save situation against the Giants. Mejia stayed in the game, insisting the episode did not affect his ability to pitch.

Anthony DiComo is a reporter for MLB.com. Follow him on Twitter @AnthonyDicomo. This story was not subject to the approval of Major League Baseball or its clubs.