PHILADELPHIA -- Only a few special people can relate to the feeling Nick Castellanos felt when he hit Spencer Strider’s 100 mph fastball for a home run in the sixth inning Thursday night in Game 4 of the National League Division Series at Citizens Bank Park.

Few people have hit a 100 mph fastball, much less any pitch at any speed in professional baseball.

But everybody can relate to the love Nick and Liam Castellanos showed each other in Games 3 and 4 of the NLDS. Liam is Castellanos’ 10-year-old son. He has been a fixture at home games  -- in the stands, in the clubhouse and on the field -- since Castellanos joined the Phillies last year.

Before every one of his dad’s at-bats, Liam scurries down the steps from the Phillies’ family section to stand next to the on-deck circle. Liam catches dad’s eye. Dad leans in to hear him talk. They chat for a moment, then fist bump through the netting behind home plate.

Then dad goes to work.

Castellanos became the first player in postseason history to have back-to-back multihomer games, hitting two homers in a 10-2 victory over the Braves in Game 3 of the NLDS, and two more homers in a 3-1 victory in Game 4. Each time Castellanos crossed home plate, he pointed toward Liam.

Liam’s reaction and smile lit up the ballpark.

Asked Saturday afternoon why he thinks their relationship has resonated with so many -- from Phillies fans to non-baseball fans -- Castellanos paused for a moment. Castellanos is a deep thinker. He chooses his words carefully.

He started by saying this is his opinion and nothing more than his opinion. It might be correct. It might not be.

“But I think in a world where more and more phoniness is presumed real, something that is real, like a dad and son that love each other, can stick out,” he said. “I think when that combines with the love of baseball, people can be attracted to it. I just think that people can relate to that.

“Because all of us as humans, we all love the same, we all hurt the same. Not everybody can relate to playing Major League Baseball, but everybody can relate to just loving life with your child or your parent.”

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Phillies fans first noticed Liam early in the 2022 season, Castellanos’ first year with the team. Asked then what Liam asks him before he walks to the plate, Castellanos smiled.

“He tells me to hit it over the fence every time,” he said.

Is that a good thing to hear before he tries to hit against somebody throwing 100 mph?

“It is a good thing because I have to swing hard to be able to do that,” he said.

Nick and Liam partied with the Phillies on Thursday night at Xfinity Live!, the entertainment complex across the street from Citizens Bank Park. It was their latest great experience and memory together. In June, Roger Clemens showed up one day at the Bank because his son Kody was on the Phillies’ 26-man roster.

Roger threw batting practice to Kody and to Kyle Schwarber.

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The Rocket threw to Liam.

“It’s a cool environment,” Castellanos said. “[Liam] gets to meet a lot of adults, so he learns to talk to a lot of adults. It’s a place where there can be a lot of growth. I still want him to be a kid and have fun, but it’s learning the line of fun and being respectful of others.”

The Castellanoses live full time in South Florida, so Game 3 of the NLDS was the first time Nick had seen Liam in a month.

It was good for the soul.

“I mean, I know that I perform the best when my mind and my body are in the same exact place,” Castellanos said. “I think when Liam is here, I'm extremely present because I'm not worried about anything else [other] than what I'm taking care of at the moment.

“This is what I do for a living. Baseball is my job, and it takes me away from him more than I would like it to. For him to be able to come and be next to me and be a part of this, I mean he's been at the house when I've sucked. He's been at the house when I've done well. He's been at the house during so many different times of my career throughout his life. So for him to be able to be next to me and witness all of it, I think, is good for his maturation in the future. So as close as I can keep him to me, you know, is always going to make me happier.”