This season, especially the last 4½ months, has been about fun, about characters, about an endless feel-good vibe that took over the Mets' clubhouse around June 1 and never let go. There were comebacks aplenty – both in the standings and in the many games that allowed them to move up in that standings.

Fun is a big part of baseball. Fun has its place.

But this is no longer about positivity and happy mojo. There's only so much a purple fast food mascot can accomplish, especially when OMG turned to SMH so quickly. The Mets are now halfway to the abyss, facing their latest must-win game on Thursday night, Game 4 of the NLCS at Citi Field, after that 8-0 throttling in Game 3.

Carlos Mendoza would surely prefer to emulate Darrell Royal, the old Texas Longhorns coach who famously said, “Dance with the one who brought you.” In fact, he literally paraphrased it less than 20 minutes after that carnage ended.

“The guys out there got us to this point,” he said.

And look: one reason Mendoza had such a great rookie year as a manager is his unwavering loyalty. The players know that he has their back. He doesn't make lineup changes out of panic. But this isn't panic. The Mets can no longer afford to follow the credo of Royal or Mendoza. There's too much at stake.

The lineup for Game 4 should look different than the one he had lined up for Game 3. But he said with absolute conviction that this would not happen. Francisco Alvarez is the obvious candidate for a break. His error in the second inning led to the first two unearned runs and cast a shadow over the 43,883 spectators eager to be the Mets' wingman on Wednesday.

He also struck out in the bottom of the inning with one out and the bases loaded when even a sacrifice fly would have gotten the ballpark back on track. He has now left 10 runners in the last two games. He is young and fights. Luis Torrens, his backup, is no Pudge Rodriguez and has only scored six goals since August 1st. But sometimes a day off is a necessary thing.

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“He’s a good hitter, a good player,” Mendoza said of Alvarez. “He’ll come over.”

So you didn't think about going with Torrens?

“Alvy is playing tomorrow,” he said. So that's it.

And the JD Martinez/Jose Iglesias DH/second base combination, which certainly seems to have reached the point of diminishing returns, will also return in Game 4. As with Alvarez, the Mets don't exactly have Luis Arraez and Yordan Alvarez ready to replace them. But Jeff McNeil (assuming he's recovered enough to play defense) and Jesse Winker should be viable alternatives.

Except Mendoza has already stopped that.

“We face (Yoshinobu) Yamamoto,” Mendoza said. “Look at his reverse splits against righties.” And sure, that's a fair point. There is no obvious advantage to balancing a left-handed lineup against him.

This may sound like someone who is a slave to analytics, but we've seen Mendoza's work all year long. That's not it, not at all. If he shows a weakness for anything here, it's a preponderance of trust. Martinez and Iglesias were crucial to the Mets' turnaround.

Martinez’s professionalism and leadership helped get them out of their spring rut. Iglesias' energy opened a window and let in a breath of fresh air within minutes of his arrival in June. And he managed to hang on for the rest of the year.

But Martinez was batting .109 as of Sept. 1 and has no extra-base hits in the postseason. Iglesias has begun to revert to the mean in this series, flailing around men on base, and on defense he could have taken advantage of Alvarez's long throw in the second, but he didn't, opening his error almost opened the door to the Dodgers rally in Game 2.

Nobody is saying that Alvarez, Martinez and Iglesias should be pushed aside and smothered in mothballs. But the Mets are now 17-0 in their two losses in the series, and neither was crucial to their win in Game 2. It feels like a change, even if just for one game, could be beneficial could.

Mendoza disagrees. And his vote counts.

“Someone will come in and make it big for us,” Mendoza insisted, and it all depends on the brand. He may not use the same rose-colored, Polyannaish words that Aaron Boone prefers, but a year with Mendy the manager has shown that he will fight for his boys as fiercely as Boone or anyone else.

That's one of the reasons the Mets are here. As a skipper this is a good quality. But so does the following: Knowing when to change the chessboard. Joe Torre famously benched Tino Martinez, Paul O'Neill and Wade Boggs in the 1996 World Series, three guys who absolutely made him dance. We remember it because it worked.

And if Mendoza's devotion to his boys is confirmed, we will remember it too.

But it has to work.