HOUSTON — The Royals’ unhappiness with their 9-0 loss to the Astros on Wednesday night can be broken down into two subsections.

The first was their inability to muster any offense against Houston starter Brad Peacock, who struck out 12 over seven shutout innings in the rubber game at Minute Maid Park.

The second was what they felt was an inconsistent strike zone by home-plate umpire Brian Knight, whom they concluded had two different interpretations of what constituted a borderline pitch.

“I don’t mind two inches off the plate, as long as we’re both getting it,” manager Ned Yost said. “We weren’t getting the same pitches.”

Frustrations reached a boiling point in the seventh inning, when catcher Martín Maldonado, who had expressed his displeasure with some of Knight’s calls earlier in the game, was ejected after striking out looking to lead off the frame.

It wasn’t the final pitch that angered Maldonado — it was the one right before that, which he felt was a ball, but that Knight called a strike.

“It was a pitch they were calling all night for [the Astros],” Maldonado said. “It was a pitch that [Hunter] Dozier struck out two times on. Bases-loaded strikeout on the same pitch. I thought it was a ball. [Peacock] was good tonight. At the same time it’s a little bit easier when you give him a little bit off the plate.”

The conversation between Maldonado and Knight didn’t last long. Given how dissatisfied the Royals were the entire night, the exchanges with Maldonado and Yost, who was also ejected, appeared to be somewhat civil.

“[Knight] said, ‘That pitch was a strike.’ I said, ‘Yeah, but the pitch before that was a ball,’” Maldonado recalled. “I just want consistency both ways, that’s all. Then he said, ‘Keep walking.’ I said, ‘Don’t tell me what to do.’ I knew I was going to the dugout. That’s part of the game, in the heat of the moment.”

The Royals struck out 17 times. Of the 12 against Peacock, eight were on called third strikes, which Yost found curious.

“Our guys know the strike zone,” Yost said. “I don’t mind an inch or two off the plate. Strike three, you can’t recover from it, I’m fine with that. Just do it both ways. My count was like 8-1. We might have gotten one. Both ways would be fine.”

Royals starter Jorge Lopez, who lasted just 2 1/3 innings and allowed six runs, noticed some inconsistencies during his time on the mound as well.

“The close pitches, they got calls,” he said. “I didn’t get calls. The pitches I threw on the plate, I didn’t get called. That made the game tough. We have to keep grinding. It’s part of the game.”

The Royals did have their chances against Peacock, albeit limited. Peacock works quickly, doesn’t nibble and relies on his slider to complement a two-seam fastball. He threw a lot of first-pitch strikes, challenging Kansas City hitters to try to attack early.

Nothing worked — in the first five innings, the Royals already had struck out eight times. The fifth frame presented their best chance to score, after they loaded the bases on two base hits and a hit by pitch.

But Adalberto Mondesi struck out swinging, and Dozier was retired on the called third strike that Maldonado later identified as one call that irked him.

“[Peacock] was throwing the ball extremely well,” Yost said. “Good slider, good fastball, with a little help from the umpire. He threw the ball really, really well.”

The Royals had not been shut out since Aug. 7 of last year, the third-longest such streak, behind the Yankees (117 games) and Twins (77). Wednesday’s loss ended Kansas City’s streak at 74 games.