WASHINGTON -- As the Mets broke camp and plotted their course for the first week of the regular season, they felt confident in their ability to compete with anyone in the National League. They also understood the nature of baseball; best-laid plans often turn sideways, as they experienced themselves when injuries struck Jacob deGrom and Max Scherzer over the final week of Spring Training.

So the Mets could not have been particularly surprised when the final stages of their four-game series in Washington went awry. Six outs away from a sweep, the Mets endured a pair of Pete Alonso misplays in the eighth inning at Nationals Park -- one on a game-tying bunt from Lucius Fox, the other on a throwing error that set the stage for Nelson Cruz’s two-run, go-ahead single off Trevor Williams. The resulting 4-2 defeat to the Nats was the Mets’ first loss of the season.

“It’s good to win the first series of the year, but dropping this one late kind of stinks,” Alonso said. “Especially for me, I didn’t want to do that. When I go out there, I don’t want to let anyone down.”

Even though the ending went wrong for the Mets, plenty did go right over the course of a chilly, wet, sometimes emotional weekend at Nationals Park. And the Mets learned three significant things about themselves.

Even without deGrom, this starting five is legit
To be clear, the Mets are not going to maintain a 1.59 rotation ERA all season. Still, some pretty telling signs have emerged that New York might not just survive, but could even thrive until deGrom is ready to return in late May or early June.

Perhaps the most important development occurred on Sunday, when Carlos Carrasco held the Nationals to a single run -- a Nelson Cruz homer -- over 5 2/3 innings. Making his first start since offseason elbow surgery, Carrasco offered immediate reason for concern when he ceded that blast to Cruz -- the ninth first-inning homer he had allowed in 13 career starts as a Met. Carrasco’s early-game struggles have been well-documented, and they’ve often led to losses.

But Carrasco escaped that inning without further damage, beginning a stretch of 15 consecutive outs to end his afternoon.

“I was able to shut it down,” Carrasco said. “Everything feels good. Every pitch was working today.”

So consistent throughout his career in Cleveland, Carrasco spoke often this spring about feeling healthy and comfortable for the first time since joining the Mets. If he can even approach the levels of production he was accustomed to from 2015-18 in Cleveland, when he averaged 180 innings and 15 wins per season, he could be one of the better No. 4 starters in baseball.

So, tack Carrasco onto the list of positive Mets rotation developments. On Opening Day, Tylor Megill showcased an augmented set of abilities, dialing his fastball up to 99 mph with a wicked changeup and slider. Scherzer is Scherzer -- no explanation necessary there. Chris Bassitt has impressed the Mets with his creativity and mound presence, not to mention his six shutout innings in his Mets debut on Saturday. And Taijuan Walker, who is scheduled to pitch Monday, appears to be healthy.

None of them are deGrom. But the Mets made a point of acquiring pitching depth around their ace for just this reason. In that regard, the early returns have been solid.

The manager has a blueprint (and lots of conviction in it)
All weekend, Buck Showalter spoke about the importance of giving everyone on his roster at least a bit of playing time.

“Shame on us if two weeks from now, they haven’t played, and we can’t figure out why they can’t contribute,” Showalter said of his bench and back-end bullpen options. “We look at them as regular irregulars.”

For that reason, Showalter drew up plans to deploy both Chasen Shreve and Williams, his last remaining unused players, in Sunday’s game. He stuck with that strategy despite the fact that the Mets found themselves in a one-run game in the eighth. Shreve, who had entered two innings earlier, allowed a leadoff single to Yadiel Hernandez. Next out of the bullpen was Williams, who gave up two ground-ball singles and Fox’s game-changing bunt. Trevor May never entered despite warming earlier in the game.

Apparently off-limits were Seth Lugo, Adam Ottavino and Drew Smith, who had all pitched in two of the Mets’ first three wins.

“It’s too early in the season to be throwing guys three out of four days,” Showalter said. “I’m going to be careful.”

That type of thinking represents a stark contrast to last year, when manager Luis Rojas used both May and Miguel Castro in three of the team’s first four games. Showalter is not only focused on the six-month picture, but he has enough job security -- as much as any manager in baseball, really -- to proceed in that manner without regrets.

“We pitched well the whole series,” Showalter said. “I’d have taken that, that whole four-game pitching. If we continue to do that, we’re going to be in good shape.”

It was never going to be that easy
Coming off three consecutive breezy wins in which the Mets’ only challenge seemed to be keeping their cool following a series of hit batsmen and a benches-clearing incident, Sunday offered a reality check. The Mets might be one of the better teams in baseball, but that doesn’t mean they’ll be able to impose their will on teams every night.

Their upcoming three-game series in Philadelphia, featuring matchups against the Phillies’ two best starters, will provide a far stiffer test against another NL East favorite. The Mets feel up to the task, to be certain, but they know there will be rough patches along the way -- if not now, then certainly at various points this summer.

“What makes baseball fun is the challenges involved,” Williams said. “The takeaway from this weekend was we had a great series win. We played some really good baseball. And I think moving forward, especially going into Philadelphia, we’ve got a lot of momentum.”