Aroldis Chapman isn’t touching 100 mph with the regularity he’s accustomed to, but on Sunday, he earned a save for a second straight day.

The lefty struck out all three batters he faced in the ninth inning of a 6-3 win over the Royals.

It was the first time he had pitched consecutive days since taking the mound three days in a row July 1-3.

“It was good to get him out there,’’ Aaron Boone said. “To get him into games is always good one, because we’re winning, obviously — and it’s usually a save situation — but also we do like our guys getting out there when it’s been a long time. It helps them stay sharp.”

That’s especially true of Chapman, who didn’t pitch for a week earlier in the month after experiencing left knee tendinitis. After that seven-day rest, he gave up three runs in a win over the Mets on July 21.

Chapman finally got in a game in the nightcap of Saturday’s doubleheader against Kansas City and pitched around a single and a walk to seal the one-run win before looking more like his dominant self Sunday.

He had fanned just three of the previous 16 batters he faced before matching that number Sunday.

“There were some really good sliders he mixed in today to finish things off,’’ Boone said.

For a second straight day, the Yankees made a significant addition to their international bonus pool money, this time sending 25-year-old lefty Caleb Frare to the White Sox in exchange for the $1.5 million slot.

Frare split the season between Double-A Trenton and Triple-A Scranton/Wilkes-Barre and the Yankees would have had to put him on their 40-man roster this offseason. The move puts them in better position to land some of the international free agents still available and came after they traded lefty Chasen Shreve and right-hander Giovanny Gallegos to the Cardinals largely to pick up more international spending money.

The Yankees signed 16-year-old Cuban right-hander Osiel Rodriguez to a $600,000 deal.

Neil Walker’s hot streak continued. Serving as the DH, the suddenly surging Walker reached base three times with a single, a walk and a hit by pitch. He’s 18-for-43 in his past 14 games.

“We’re seeing what we’ve seen from Neil Walker his entire career,’’ Boone said. “Right now, especially with some injuries and Aaron [Judge] going down, there will be a lot of at-bats available to him. We need him to be big for us.”

Zach Britton didn’t pitch Sunday, but that wasn’t because of what happened during his rough Yankee debut on Saturday.

“I think he got in a little bit of a rut there for a couple of hitters,’’ Boone said of Britton, who gave up a run in one inning during their win in Saturday’s nightcap. “It’s important to remember this is still a guy, although we think he’s very much back, [who] had Achilles surgery [in December], so it’s been a different kind of year for him bouncing back. I don’t think anything [Saturday] was alarming… I’ll bet on that dude every day.’’

Right-hander Domingo Acevedo was placed on 7-day DL with Trenton with upper arm soreness after being removed from his start Saturday. … Sunday was the 20th sellout of the season, tying the record set in the new stadium in 2011.