Get the popcorn ready. The New York Mets are trying to script a thrilling ending by turning what looked to be a losing season into a September push for the playoffs.

“It’s the best time of year,” Mets outfielder Jesse Winker told SNY. “I’m definitely excited and I like our chances. You’ve just got to keep going one day at a time.”

The Mets entered the first day of September two games behind the Atlanta Braves for the final three wild-card spots in the National League. A season-high eight games over .500, the Mets finished August 72-64 by winning seven of their last 10 games and three straight.

After closing out a three-game series with the struggling Chicago White Sox on Sunday, the Mets return to Citi Field for what should be a raucous three-game series with the Boston Red Sox before finishing a crucial six-game home stand with three against the Cincinnati Reds. A team that was 11 games under .500 in June, the Mets have rallied to accomplish their goal of battling for a post-season berth in the final month of the regular season.

“We’re really in the race right now,” pitcher Jose Quintana said in Chicago. “Every single game, every single play means a lot for us. We’re pushing each other and we feel really good. At this point, we’re playing our playoffs right now. Every small thing is really big for us and means a lot.”

The New York Yankees (79-57) would have to collapse not to make the playoffs, entering September atop the American League East. The only question is whether they’ll be one of the top two division winners to receive a bye into a Division Series or wind up in a best-of-three series in the Wild Card round with the higher seed hosting all three games. The Mets just want to be playing in October.

“Everybody knows the mission is winning day in and day out,” shortstop Francisco Lindor told reporters in Chicago. “No matter what happened yesterday or what’s going to happen tomorrow, you’ve got to stay locked in for today and that’s what everybody has been doing. We’re trying to accomplish the daily goal, which is winning.”

The Mets don’t have an easy path. They face the Philadelphia Phillies, the NL East leaders, seven times this month and face the Atlanta Braves in a three-game series in Atlanta before ending the regular season with three games in Milwaukee.

It’s imperative the Mets offense remains hot and their pitching holds up. Mr. Lindor, who entered September hitting .269 with 28 home runs and 79 RBI, and third baseman Mark Vientos (.279, 21, 57) have sparked the Mets offense for much of the second half, while Mr. Winker (.342) has swung a hot bat in his 26 games with the Mets.  He went 3-for-3 with two RBI in the Mets’ 5-3 win over the White Sox on Saturday.  It was his third straight multi-hit game. “He’s locked in now,” Mets manager Carlos Mendoza said. “It’s been quality at-bat after quality at-bat.”

First baseman Pete Alonso also added his 30^th home run of the season on Saturday, joining Mike Piazza as the only Mets to hit 30 home runs in three consecutive seasons.

Closer Edwin Diaz (15 saves) has to be consistent. He gave up a walk-off homer run in San Diego but rebounded with two strong outings before getting a rest Saturday.

“I’ve got to do my job and keep winning games,” Mr. Diaz said. “We’re chasing a playoff spot and we’re really close. We’ve just got to keep playing good in these games and keep doing what we’re doing and we’ll be fine.”

The Mets have the highest payroll in baseball at $311 million, while the Yankees are second at $306 million so being in playoff contention shouldn’t be a surprise. But nothing is a given, especially after the Mets had such a slow start.

“We know we can compete against anybody,” Mr. Lindor said. “I know at times we haven’t played our best against teams that are not in contention. But against teams that are competing, it seems like we play very well against them. That’s a good sign.  We just have to find a way to be in the post-season and then let anything happen.”

Designated hitter J.D. Martinez has made post-season appearances with the Los Angeles Dodgers, Detroit Tigers, and Arizona Diamondbacks. He warns his teammates not to focus on what other teams are doing.

“It’s easy right now for the young guys to get caught up in the standings and looking at it all,” Mr. Martinez said. “One thing I preach is let the media and the fans look at that.  Let’s just focus on us and just keep going and having fun and whatever happens, happens.”