ST. LOUIS -- It’s the matchup baseball was denied seven Octobers ago. The one Nationals general manager Mike Rizzo so vigorously defended while others in the industry wondered (out loud, in some cases) how and why Washington could be so certain that this was the necessary move for the individual and a franchise.

But Rizzo made it anyway, assuring that Stephen Strasburg’s only role in the Nationals’ 2012 National League Division Series matchup against the Cardinals would be as a spectator. What happened next (Pete Kozma, anyone?) still haunts the Nats, and it only amplified the questions surrounding the organization’s decision to take the ball out of the hand of their prized starting pitcher.

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Now, on Monday, as this NL Championship Series shifts to D.C., Strasburg will make that start against the Cardinals that he once wasn’t allowed to take.

“Once you start thinking about how things could have been or what things might happen, it takes your focus away from what your job is,” Strasburg said, downplaying the then and now. “I try not to look in the past, try not to look in the future, really just try and be in the moment.”

That moment, for a Nationals team marching home with a 2-0 series lead, looks quite auspicious. Facing the Cardinals in October for the first time since 2012, the Nats turn this series over to Strasburg after watching Aníbal Sánchez and Max Scherzer combine to allow two hits over 14 2/3 shutout innings at Busch Stadium.

“Hopefully he does what Sanchie and Scherzer did the last two games,” said Nationals manager Dave Martinez.

This is the sort of deep October run the Nationals envisioned all those years ago when they opted to sit a healthy Strasburg. Preserve his arm now, they believed, and they’d be ready to ride it for years to come.

The organization let Strasburg pitch every fifth day that season until a three-inning appearance on Sept. 7 brought his innings total to 159 1/3. Then, they followed through with the vow Rizzo had made back in February: That would be it for the third-year Major Leaguer.

At the time, the Nationals boasted the Majors’ best record (85-53) and top run differential (plus-133). They were cruising toward the organization’s first playoff berth since relocating to D.C.

“We’ll be back,” Rizzo famously said when asked, upon clinching the division title, why the club wouldn’t make an exception for Strasburg in order to improve the club’s October odds.

It was a bit braggadocious, but also defensible. The Nationals had a budding core. Their window seemed only to be opening. And Strasburg, still in the naissance of his career, was also still working his way back from Tommy John surgery.

Over the next four years, however, Strasburg made only one postseason start due to circumstance and injury, the latter of which was the one thing the Nationals had been trying so hard to prevent.

It was a confluence of events that has left Strasburg, like it or not, to carry the weight of that 2012 decision -- one passionately supported by his agent, Scott Boras -- on his right arm ever since it was made for him. And much like the expectations placed on the first-overall Draft pick when he was plucked from San Diego State University in '09, it’s become a focal part of his journey.

The what-if questions became a shadow Strasburg couldn’t shake.

“Well, I think anytime you add an arm as great as Stephen Strasburg to a rotation, it's going to help,” Cardinals starter Adam Wainwright said, looking back on that 2012 NLDS. “You could always point to something and say he would have thrown nine shutout [innings], but you just never know that. We'll never know, will we?”

Which is perhaps why, seven years later, the storyline hasn’t completely faded. How Strasburg would have impacted that five-game series can’t be derived from data. His replacement in that series, Ross Detwiler, allowed an unearned run in a six-inning start. On the other hand, the other three starters combined to allow 14 runs over 18 innings.

Might Strasburg have been the one on the mound to protect the six-run lead the Nats enjoyed early in Game 5? Could he have been an asset out of the ‘pen? Would he have made a difference? Rizzo refuses even to entertain the topic.

“We are certainly not going to talk about 2012,” Rizzo said. “We’re going to talk about 2019 and playing the St. Louis Cardinals. He’s one of the best pitchers in the game. He’s been one of the best pitchers in the game. He’s a hard-working guy who really knows the art of pitching and has gone from really a stuff-guy thrower to really a consummate Major League pitcher with a great repertoire and a great work ethic. And we couldn’t be happier for his success.”

Maybe these are the wrong questions anyway. Perhaps the most pertinent now is: Did it all matter?

If only the answer were obvious. The front office has always stood behind the decision, pointing to Strasburg’s success since as a byproduct of his deliberate development. And in that, there’s certainly a case. Strasburg, an 18-game winner who led the NL in innings this season with 209 -- Trevor Bauer had 213 between Cleveland and Cincinnati -- will likely land a Top-5 finish in the NL Cy Young Award voting this fall.

Strasburg has become a star in October, too, posting a 1.45 ERA over five postseason starts.

“I think what we did in 2012 is the reason why he is the type of pitcher he is now,” asserted first baseman Ryan Zimmerman -- who, along with Kurt Suzuki, is one of just two '19 Nats to be teammates with Strasburg in '12. “It was a highly debated issue. But at that point, as tough a decision as it was to not pitch him, I think they were honestly looking out for the best interest of the player.”

If it was durability the Nats ultimately desired, well, there also hasn’t been such cause-and-effect. Strasburg has endured eight stints on the injured list since 2012, and he has reached 180 innings pitched in just three of seven seasons since.

What could cap the questions and ultimately justify the course, however, would be for Strasburg to anchor a World Series-bound rotation. And when he throws his first pitch on Monday, he’ll do so with the Nationals sitting two victories away from advancing to the Fall Classic for the first time in franchise history.

“When he’s on the mound, he’s as good as anybody in the game,” said Rizzo. “He’s had a few injuries that have taken him out of the rotation at times. He’s a guy we count on heavily here and a guy who is near and dear to the heart of the Nationals.”