This was always the strongest argument on this side of the great debate as to whether Pete Alonso should start his season in Syracuse or Queens. The games in April count just as much as the ones in September. In a National League East that promises to be a great stakes race covering 162 furlongs, every win matters.

And if you finish a game or two short, everything you did — or didn’t do — in April will haunt the winter every bit as much as anything you did — or didn’t do — later on.

So Alonso started hitting the moment he unpacked his bags in Port St. Lucie. He hit for power. He showed a propensity to hitting it the other way, which has become a team-wide mantra. He was a good teammate; all you had to do was watch him interact with Dom Smith — his biggest impediment to Citi Field — to see that.

He did what every kid going back to the beginning of baseball time wants to do when they step into big-league camp.

He made it impossible to keep him on the farm.

“They told us that if you performed well, there would be a reward for that,” Alonso said as he was getting ready to leave Citi on Sunday afternoon, a 12-9 loss to the Nationals in which he clobbered his second home run in as many days. “I trusted that, and knew if I just took care of my own business, everything would fall into place. And it did.”

Beyond that, though, and beyond the splendid numbers he’s crafted across his first week and a half as a big leaguer — three homers, 11 RBIs, a .382 batting average, a 1.256 OPS — is a simple fact:

The Mets are 6-3.

Without Alonso, they are probably not 6-3.

Now, that’s impossible to absolutely quantify. It’s possible Smith could have gotten off to just as scorching a start (he does seem to have found himself too, after all). But it is certainly fair to say the Mets’ comeback win Saturday wouldn’t have been as feasible without Alonso’s eighth-inning, end-of-the-bat blast that started the decisive rally. It’s fair to wonder how the shaky Mets bullpen would’ve done with a skinny one-run lead in Miami last Monday as opposed to the four-run cushion Alonso’s first career blast gave them.

This is what Brodie Van Wagenen said the day before the season opened, when he announced that Alonso had, indeed, made the big club, that the Mets had, indeed (barring any unforeseen or unwanted circumstances) opted to forfeit a year of control in order to have Alonso with the team from Day 1:

“I’m not of the mindset that we should be sacrificing the best product for the fans and the best product for the other 24 guys in that clubhouse to save service time or potential future money six years down the road,” he said.

“If Pete Alonso is good enough to have six consecutive years without ever having a hiccup or having to go to the minor leagues, that’s a good, high-class problem for the player, it’s a good, high-class problem for the organization and it’s a reward fans will be fortunate to see.”

Now, it isn’t just the wins and losses that measure his importance. Sunday, for instance, the Mets-Nats game had long since drifted into the realm of the unwatchable but a few thousand extra waited longer than they’d otherwise want to because Alonso was due an at-bat in the seventh inning. And when the ball exploded off Alonso’s bat, even a meaningless blast made Citi come alive.

There is value to that. We can let the accountants argue whether the fiscal value is the equivalent of playing the service-time game. From a baseball standpoint?

“It feels so good to contribute,” Alonso said Sunday.

In his hands was a copy of “Crossing the Line,” the autobiography of hockey player Derek Sanderson. Alonso is more of a Lightning fan but he’s marrying into a Boston family and, well, we all make our sacrifices when we choose the altar.

“He was a bad-ass,” Alonso said of Sanderson. “I’m trying to get into his head a little bit.”

That internship is off to a flying start. For Alonso. More so for the Mets.