What happened here Thursday night at one point would have been some sort of freak show but by now is called, rather plainly, “baseball.” Two men, each with a ligament in his elbow that used to function in another part of his body, hurled baseballs from a mound. Matt Harvey’s first fastball to the Washington Nationals sailed in at 94 mph. Stephen Strasburg’s first fastball against the New York Mets rang up at 96, and it came after a slider clocked in at 90. The Tommy John Industrial Complex churned forward.

This surgery, which Strasburg underwent in 2010 and Harvey in 2013, is commonplace now, and pitchers not only hope to have long careers after undergoing it, they expect to. But the truth of the matter is we have no absolute road map out of these woods, one that applies to all comers.

[Nationals hammer Matt Harvey in 9-1 thrashing of Mets]

The latest example, on one May evening: The pitcher who was protected performed, and the pitcher who was exposed looked nothing short of lost. The fact that Strasburg threw six innings of one-run ball in a yawner of a 9-1 Nationals’ victory was secondary — even as he moved his record to 7-0 and lowered his ERA to 2.80, striking out 10.

The primary issue, not just on this night in Queens but as the National League East race takes shape, is Harvey. This is full-on crisis mode, with Tommy John surgery and how it was handled as the backdrop. Harvey managed just 2⅔ innings, the shortest of his 74 career starts. He gave up a career-high nine runs (though only six were earned). He walked off the mound utterly confused, his ERA at 5.77, his opponents’ batting average a staggering .325, leaving his manager wondering whether he could even afford to start him next week, when he’s due to face the Nats in Washington.

Stephen Strasburg gives up just one run on six hits and strikes out 10 for the Nationals at Citi Field. (Frank Franklin II/AP)

[At quarter mark, Nats are off to best start in team history]

“There’s as many answers as I’d like to find as you guys are looking for,” a glassy-eyed Harvey said afterward. “Everybody saw the game. It’s pretty obvious what happened. I’m not happy about it. I know nobody else is. Got to pick up tomorrow and, like I’ve said all along, start over and keep looking for answers.”

The Mets, currently, don’t have them. Though Harvey might have escaped a seven-run third — that’s right, seven-run third — had shortstop Asdrubal Cabrera properly fielded a double-play ball, the Nats scalded balls off him — a single from Bryce Harper, a double from Anthony Rendon, a triple from Ben Revere, Daniel Murphy’s homer. In his last 81/3 innings over two starts, Harvey has allowed 19 hits, eight for extra bases.

When Manager Terry Collins came to get the ball in the third, Citi Field booed.

[Manfred rips Orioles’ position in revenue dispute with Nationals]

“I feel bad for him,” Harper said. “. . . He’s one of the first guys to come back and go zero [innings] to 200. That’s tough.”

The performance of these two pitchers, among the highest profile in the sport, was always going to be cast against each other Thursday night regardless of the result. But step back for a moment here and consider that what Harvey and Strasburg went through to take the mound Thursday night was once a grand experiment.

“Dr. Frankenstein,” Nationals Manager Dusty Baker said before Thursday’s matchup. “You take something over here, put it over here, and go over there and put something else over here. I was like, ‘Man, Frankenstein was way ahead of his time.’ ”

[Jayson Werth’s adjusted contract will defer $10 million]

That is what we all need to be reminded of occasionally, that somehow what this experiment is now somehow viewed as normal. Tell that to the guys in the Los Angeles Dodgers training room that day back in 1974, when orthopedic surgeon Frank Jobe walked in and started talking about the predicament of John, then a 31-year-old left-hander who was off to such a fine start.

“It was something about a ligament,” said Davey Lopes, a Dodgers infielder back then and the Nationals first base coach now. “That’s all I remember, that it wasn’t good, that he was going to be out for a long time — and it was uncharted waters. It had never been done before. It sounded kind of crazy.”

The waters Strasburg and Harvey took to were much more charted, but they can be choppy still. As Jeff Passan expertly details in his new book “The Arm”, Tommy John surgery is now a baseball epidemic. But frequency and familiarity doesn’t bring concrete answers on how to handle these problems when they happen – particularly to aces who expect to perform. An unnecessary review: The Nationals, then in first place, prohibited Strasburg from throwing more than 1591/3 innings in the summer of 2012, a decision mocked across the country but still embraced internally. Now, he appears better than ever. Related?

[11-year-old Mets fan has ‘amazing’ game of catch with Max Scherzer]

“We certainly don’t have a hard-and-fast rule about numbers of innings and the way we allocate those innings throughout the season,” Nationals General Manager Mike Rizzo said Thursday. “Each case is individual. We had a general innings limit in mind, but as I’ve said before: It was more about the eye test than the number.”

Last summer, the Mets wanted Harvey on an innings limit, too — until they found themselves in first place in August. Then things got dicey. He eventually pitched deep into October, and when he was finally lifted in the ninth inning of Game 5 of the World Series, he had thrown 216 innings. Competitive circumstances overtook health concerns, and no Mets fan would have had it any other way last fall.

But now, there is confusion. “At this point,” Harvey said, “I have no idea.”

So for a night, with two pitchers who endured this bizarre procedure that is now considered rote, there was a contrast. That had Collins not only evaluating whether Harvey would make his next start — “We’re going to look at that,” he said — but also using Strasburg as an example for Harvey.

“That guy that pitched tonight for them, he had a couple of mediocre years, and now he’s resurged,” Collins said. “. . . [Harvey] went above and beyond last year, and I’m not sure he’s recuperated from it.”

His production, both Thursday night and to this point in the season, would indicate he hasn’t.