The Post’s Jonathan Forsythe says we should be worried about Stephen Strasburg’s pitching arm after his start on Monday night. (Post Sports Live)

Stephen Strasburg’s arm is “structurally perfect,” and he merely felt “irritation in his forearm” Monday night in Atlanta, possibly because of normal pregame use of a stimulation machine, according to Nationals General Manager Mike Rizzo. Strasburg is scheduled to make his next start.

“The irritation was on the other side of the elbow from his [Tommy John] surgery,” Rizzo said. “There’s no problem. He’s strong as an ox.”

Move along. There’s nothing to see here. Except that there is.

When Strasburg, who arrived in the majors with an unprecedented combination of stuff and command, throws one pitch exactly where he wants it, then misses his target by two feet on the next, that’s a red flag. But what’s the message? Is he a competitor toughing out a quality start on a bad night?

When three of his four walks are to leadoff men and his mechanics are obviously a mess, what’s the reason? High-anxiety overthrowing? Or a tip-off that he’s compensating for an arm problem that’s about to surface?

When, start after start, Strasburg has little command in the first inning (10.50 ERA), yet is dominant thereafter (1.49 ERA after the first inning), does that mean his shoulder, elbow or forearm feels tight until they loosen up? Or is he just a 24-year-old pitcher who has been losing April battles with his workout-freak physique that spews nervous energy?

When Strasburg shakes his arm between pitches, is that a precursor to injury, an unconscious habit to flick off sweat or a sign that his wires get crossed when his perfectionist demands meet the reality of base hits?

“Strasburg’s rolling his shoulder like he can’t get it loose . . . that would concern me if I were the Nationals,” Rick Sutcliffe said on national TV. “I would come out right now with the trainer. If there’s nothing wrong, then let’s not be doing that anymore.”

If Strasburg’s glorious pitching arm turns out to be made of Waterford crystal, we’ll find out soon enough. He’s finally off any pitch or innings limit. He’s physically mature enough and healthy enough to be turned loose. If he succumbs, we can all feel awful for him — except for the Reverse-W-delivery pundits who can say, “We told you so,” if they want.

Right now, there is no concrete reason to think Strasburg isn’t healthy. His 93rd and last pitch of Monday’s outing, during which he allowed just two runs in six innings, was his fastest of the night: 98 mph. He blew away Justin Upton with back-to-back heat in a fifth-inning jam then fanned the side, all swinging, in the sixth. He can’t look much better.

“Come on, 97, 98 to the last hitter? That’s not an injured pitcher,” said a scout who requested anonymity. The Nats should “be more worried about his woe-is-me body language. He’s got this invincibility complex. ‘How did that guy get a hit off me?’ Then his shoulders slump.

“He comes out over-amped, over-throwing. He walked Jordan Schafer, who’s been released twice, three times. With his stuff, just say, ‘Here it is. If you hit it, God bless you.’ That’s what bothers me.”

That’s typical of the nagging Strasburg gets from many, including me at times, though my name’s on it. He is enormously competitive, disciplined and driven. He aspires to an implacable Roy Halladay mound demeanor. But since a strong start on opening day, he has looked rattled at times, and after the national beating he took last year for merely following team orders, he may feel picked on. Who wouldn’t?

There’s an old baseball expression: “The great ones play above the breaks.” Somehow, through talent and athletic arrogance, perhaps mixed with a bit of disdain for the opinion of mankind, the best ballplayers ignore everything that is not of use to them. They perform outside, above, or in defiance of errors by teammates, unfair criticism, poor run support, lousy umpires, dumb media and the infuriating way that the best hitters keep ruining their almost perfect pitches. A bad break, what’s that?

But that’s a process that takes a long time — not just 51 starts spread over four splintered, injured, chopped up partial seasons.

The real pain Strasburg felt against Atlanta may be the same discomfort that has bothered the Nats throughout their 13-14 April: growing pains. That sounds innocent and easily curable. But it’s tricky. Controlling competitive anxiety and channeling it into focused performance is at the core of clutch performance. Strasburg had that gift when he arrived in the majors. So, it’s there. The Nats lacked it last October and have been without it for a month. But they can gain it.

Perspective, within a game or a season, is hard to acquire. It’s tough to step back yet almost shocking when you do. The Nats’ play has been heckled with cries of, “Where is that exciting team from last year?” Yet that team is right before our eyes. Just 365 days ago, the Nats where in the midst of two months of mundane play, going 27-26. That’s almost a third of their entire season! The difference? That stretch came immediately after a 14-4 start. It wasn’t noticed. But it happened.

That problem of perception applies to Strasburg. He has pitched six games: Five were quality starts, and in four, he gave up two earned runs or less. He has plenty to learn, but only in the context of how good he already is.

“He’s still learning to deal with being a number one starter,” Rizzo said.

As long as the Nationals are correct about “no problem . . . strong as an ox,” not just whistling in the dark, Strasburg will have time to figure out how to control his emotions and his mechanics, how to blend his pure stuff with proper strike-throwing aggression. Then the day may come when, even on nights like Monday, he can pitch above the breaks that distract him now.

What a bad break that will be for everyone else.

For previous columns by Thomas Boswell, visit