Mateo López is old enough to understand what his dad, Jorge, does for a living.

The 11-year-old son of the Cubs’ reliever knows his papá pitches in the big leagues, a claim not many can make.

But when his papá, threw his glove into the crowd in frustration in his final game as a Met, Mateo was confused. So López sat him down and used it as a teaching moment.

“He didn’t understand,” Jorge López said. “I had to sit him down, show him the video, tell him what papá did and what happened and explain that there are things in life that are going to happen, and you have to know how to have patience and a manner in which to think well about certain situations.”

After that moment, López gave a postgame interview where he said he was “the worst teammate in probably the whole [expletive] MLB.”

The interview — done in his second language, English — was misinterpreted as being on “the worst team in probably the whole [expletive] MLB.”

He was designated for assignment the next day, went unclaimed and became a free agent. It was an out-of-character moment, López said, and while he was frustrated with how it went down, he instead chose to use it as a learning experience.

“We always learn from bad moments,” López said. “It’s something that throughout life, we learn our capacity to have an understanding about things that aren’t respectable in our game. For me, it’s unbearable to not respect the game. I don’t take joy in doing that after my frustration.

“I’m a person that likes to be simple, work hard and show a good work ethic, be efficient, be a professional on and off the field. That’s something that is the best thing that can happen to you apart from results.”

When López was released, he sat for a week, not knowing what might transpire and if he’d ever even pitch in the majors again. But when the opportunity with the Cubs arose, it was a match made in heaven.

The Cubs were a team with a need for bullpen help — when he signed, they were hampered by injuries and ineffectiveness, so the ability to add a former All-Star closer was a no-brainer.

For López, it was an opportunity for a reunion.

Craig Counsell was his first manager when he reached the big leagues with Milwaukee in 2015 and 2017. Just as important, though, was the Cubs bullpen coach, Darren Holmes, who was his bullpen coach in Baltimore in 2022 when he was an All-Star.

“Holmes, for me, was like a father when I got to Baltimore,” López said. “When I got there, I had the worst habits at that point in my career. I thought I was going to be out of baseball. But thank God because he gave me the opportunity to have a coach like [Holmes].

“He’s always shown care to me and we worked really hard in 2021 and 2022 which gave me my great season as a reliever. To have him here is another privilege.”

The early returns might suggest the reunion is paying off. In 5 games (5.2 innings) López has a 1.59 ERA and 1.24 WHIP.

Thursday night in Baltimore, López was averaging 96.7 mph on his four-seam fastball, 97.2 on his sinker and topped out at 97.3 mph and 98.5 mph, respectively on each pitch. It’s a small sample, but it could show him returning to a semblance of who he was at his best.

This season, he had been averaging 95.2 mph on his four-seamer and 95.1 on his sinker. In his All-Star campaign in 2022, he was sitting 97.3 mph on his four-seam and 97.7 on the sinker. That velocity increase can help him continue to pitch himself into leverage situations.

It’s a testament to the work López has put in with Holmes and the rest of the Cubs’ pitching infrastructure — like he did in 2022 when he posted a 2.54 ERA, 1.18 WHIP with 23 saves for the Orioles and Twins.

“We worked on the mental side, the mechanical side so that I felt comfortable and confident in each pitch because he knew I had the ability, I had the velocity, the movement,” López said of what he learned from Holmes. “All I was missing was a small detail with a bit more focus on the field. And, well, it was about having confidence pitch after pitch. It was up to me to make the adjustments in the game and give it my best.”

López is hoping the hard lesson he learned and had to teach to Mateo can reap massive benefits for him and the Cubs’ bullpen.

“To be able to finish with an education — it wasn’t what I planned — I never imagined in my life that would happen,” López said. “But an opportunity to come here with the Cubs came and I’m thankful to Counsell who gave me the opportunity to be able to stay in the game, be in the game, believe in me and my ability.

“Try to give the best example in the clubhouse and off the field is a privilege for me.”