WASHINGTON — Feeling forced to defend wrongdoing in the interest of supporting teammates sits somewhere near the top of Buck Showalter’s list of annoyances from 45 years in pro baseball.

Showalter mentioned this pet peeve twice on the second day of his first regular season as Mets manager — once after Pete Alonso was left with swollen lips and a bloodied mouth in the opener and once more hours later, after Francisco Lindor needed X-rays and a concussion test. Both Mets stars were drilled with pitches near the face in back-to-back games, and it was clear entering Saturday’s series continuation where Showalter stood on Nationals’ pitchers throwing up and inside.

“There’s nothing worse than when you have to support something that’s wrong that your team does,” Showalter said. “That’s really frustrating for a manager and players. Usually the players take care of that themselves. I’ve had young players get the team in some stuff that we shouldn’t have been in. That’s frustrating. It’s also frustrating when you are on the other side of it.”

The question no one really could answer Saturday without risk of suspension: Will the Mets retaliate over the weekend? It would’ve been difficult to do so Friday after Nationals pitcher Steve Cishek and third-base coach Gary DiSarcina were ejected for acting as aggressors in a benches- and bullpens-clearing skirmish set off by Lindor’s knockdown. Both sides were warned, meaning an immediate ejection likely would have followed the next hit batsman.

“I wish it never happened,” Cishek said. “Maybe I looked intense out there. I was in the moment. I wasn’t trying to go after them. I was just saying I’m not doing it on purpose. They kept counting how many times we’ve hit them.”

Four was the running total after two games.

Showalter brought the pregame lineup card to home plate Saturday because he anticipated a preemptive double warning. There was nothing as awkward as asking ace Max Scherzer to drill one of his former Nationals teammates standing in the way of having new Mets starter Chris Bassitt make a statement.

“I’ve got a feeling about how it’s going to go,” Showalter said. “This is the first time I’ve gone to home plate in games two, three and probably four.”

Just like Alonso was back in the lineup the day after he was hit, Lindor returned Saturday to shortstop.

“I feel good, so I want to play,” Lindor said. “I came in and had to run through all the different tests so they could clear me. I’m in a good spot.”

Lindor admitted his cracked tooth “hurt a lot” trying to eat, but that is a minor price to pay for what could’ve been a major injury if not for the chin flap attached to his helmet absorbing some of the blow from an 88-mile-per-hour fastball. He said he used the protective gear “on and off” last year but “thank God I had it on” Friday.

“It hurts like if I have a cavity,” Lindor said. “Hopefully, the Mets have good insurance.”

Jokes aside, safety in the batter’s box is no laughing matter. If the Nationals’ pitchers are having trouble gripping the baseball or are facing early-season control issues, should they be pitching inside? It is a tool for keeping hitters from crowding the plate and thus lessening the strike zone.

“That’s a great controversy that you want to start,” Lindor said when asked about the fine line. “I will not . I’ll let you figure that one out.”

Hours earlier, however, Lindor said, “They are pitching up-and-in and missing spots. I’m not going to get into whether it was intentional or not. It’s a game.”

Showalter is in no mood to hear that the beanballs are “unintentional.” The apology phone call he received from Nationals manager Davey Martinez — and the two in-person apologies from Nationals pitchers Mason Thompson to Alonso and Cishek to Lindor — calmed tempers more than any excuse-making would have, but the umpiring crew could be forced to weigh intent and ejections again.

“They understood our frustration,” Showalter said. “They understand the emotion of that moment and how you diffuse it.”