Kevin Gausman’s not quite starting in his home ballpark yet, but he is getting much closer.

On Tuesday evening, the Orioles’ heralded 22-year-old right-hander will make the second appearance of his big league career, and this time it’s 40 miles south of Camden Yards at Nationals Park. He’ll have more fan support than he did last Thursday at the Rogers Centre in Toronto.

“I’m definitely excited. I think I’ll have a little bit of a following. In Toronto, there were like fiveOrioles fans there. So this should be cool,” said Gausman, who had never been to Nationals Park before. “It should be about half, maybe close to 50-50. It will definitely be fun. And a lot different from Toronto. But I don’t think anything will compare to being in Camden for the first time.”

That should happen this Sunday against the Detroit Tigers’ explosive offense. But he has to get past the Nats first. And Gausman believes he needs to be better than he was in Toronto, at least when it comes to key situations.

“I left some balls up in two-strike counts, sort of what I was doing early in the year in [Double-A] Bowie. I just wasn’t making my pitches late in the count and got into trouble,” said Gausman, who allowed four runs in five innings in a loss to the Blue Jays. “That’s something that is not like me and it is something that’s kind of frustrating. Coming in here, I’m just trying to get back to what I had been doing — pounding the bottom of the [strike] zone.”

One less worry for Gausman is that he most likely won’t have to face the Nationals’ 20-year-old outfielder Bryce Harper, who aggravated his left knee injury Sunday and may not play again until he can DH in Baltimore later this week.

Gausman and Harper were teammates on a USA juniors team in 2009, when Harper was a catcher and actually caught Gausman at times. Gausman said he had looked forward to the challenge of facing Harper, but he figures he can’t worry about who is or isn’t in the lineup.

“For me, every guy in that lineup is a tough guy right now. There wasn’t one guy that I was more excited to pitch to in Toronto than anyone else. I was looking at all of them the same,” Gausman said. “The dynamic that [Harper] is, the type of player he is, is a little bit different. He’s an impact guy, so that would have been fun, just to kind of see.”

Gausman likely will also get another big league first Tuesday — an at-bat in a National League park. Orioles manager Buck Showalter isn’t thrilled that the rookie will be at the plate in his second big league game.

“We’ll make sure we’ll get an elbow pad for Gausman [Tuesday]. Unfortunately, he’s a left-handed hitter [and his right arm is exposed],” Showalter said. “I know he’s excited for it. I’m not excited about it.”

Gausman said the past week has been a whirlwind for him. He said he went back to look at the tape of his first start, to see what he could do better, and it all seemed like a dream.

“It’s like there was a screen over my face, like I was almost not even there. It’s crazy,” he said. “I watched the video, and I was like, ‘I don’t even remember that.’ But it was awesome.”