Take a closer look, though, and the mental toughness is equally impressive.

That toughness was on display in the strangest of first innings Sunday at Ed Smith Stadium, where the Orioles scored three runs (one earned) without hitting one ball hard. Schmidt struck out the first batter he faced with a nasty two-seamer, but there was so much action on the pitch it got away for a passed ball and Austin Hayes was safe at first base.

Wind-blown pop-ups found green grass, but Schmidt kept his composure, worked a 1-2-3 second inning as the Yankees tied it 3-3 in the top of the inning in what ended a split-squad 5-5 tie.

This was Schmidt’s fifth appearance and first start of the spring. He owns a 2.57 ERA.

Here is where the mental toughness comes from for the 6-foot-1, 200-pounder, who was a star at South Carolina but did not pitch his first year after being drafted because he underwent Tommy John surgery.

“My family kind of instilled it in me at a young age, my father was a colonel in the Marine Corps, he retired three years ago,’’ Schmidt, 24, told The Post. “He was deployed twice to Afghanistan, once when I was in middle school and once when I was in high school. He flew F-18s.’’

That will do it.

The F-18 is a twin engine, mid-wing, multi-mission tactical aircraft that is highly maneuverable and at the switch of a button allows the pilot to perform either fighter or attack roles or both. It is what the Blue Angels fly.

“The first deployment we went out, Clarke was 8 years old,’’ Dwight Schmidt said. “You are asking a young man at 8 to be the man of the house. You grow up pretty quickly when he sees funerals of [family] friends and stuff like that.’’

“I was really tested at a young age,’’ Clarke said.

There was another challenge.

Clarke’s older brother Clate, who pitched at Clemson and in the Tigers and Reds organizations, battled cancer in college.

“I’m very strong in my faith,’’ Clarke said, “and my family is such a good support staff. They instilled in me to always roll with the punches and kind of have that mentality: ‘This too shall pass.’ ’’

Don’t expect a couple cheap hits to mess with that mentality.

Dwight Schmidt, who was at Sunday’s game, is now a pilot with Delta Airlines. He flew the F-18 for 20 years and continued on in the Marine Corps Reserve for 10 more years.

He taught his children how to problem solve and not to dwell on the past.

“In the aviation community, we call it compartmentalization,’’ Dwight explained. “You keep things in perspective and don’t let other things bleed over. Clarke learned that growing up in a military family. I’ll give you an example: If I’m fighting another airplane and I make a mistake, I can’t live on the mistake that I made because he may make a mistake in the future. You may die from that mistake.

“Clarke is a strong young man and you saw that today in the first inning. You never saw him waver.’’

Said Clarke, “Seeing those guys in the military, they are amazing. My father always told me, ‘Nobody is going to be tougher than you.’ On the mound I try to pitch with a chip on my shoulder and be very competitive, and my brother is 2 years older than me and was always better than me so it was just naturally competitive growing up. I always kind of had that grittiness so situations like today in that first inning, I kind of enjoy it. It was good to get out of the stretch and be in those moments where you kind of got to get an out.’’

Lean in.

“Just grit your teeth a little more,’’ Clarke said with a smile.

During his father’s second deployment, Clarke was a senior in high school. Dwight is quick to credit his wife, Renee, for keeping the family together while he was gone.

“Clarke has learned the thing behind him can’t affect him,’’ Dwight said. “It’s the thing in front.’’

Right now, a bright Yankees pitching future is in front of Clarke Schmidt.