NEW YORK -- Hours before the Mets’ Subway Series games at Citi Field this week, Pete Alonso emerged from the clubhouse ahead of his teammates, bat in hand, and began cranking as many home runs as he could. Several went to the batter’s eye in straightaway center field. Others, as far as the second deck in left.

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For Alonso, it was a chance to practice before he competes as the No. 2 seed in the Home Run Derby -- his first organized derby of any kind since college. It also offered an opportunity for Derek Morgan, Alonso’s second cousin, to perfect his batting-practice fastballs. Morgan flew to Queens for the practice sessions shortly after Alonso invited him to throw to him at the Derby, scheduled for Monday night at Progressive Field in Cleveland.

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“I’m just blessed that he asked me,” Morgan said. “Him and I grew up loving the game, and I’m just honored that he asked me. Hopefully, I groove it in there for him and he takes care of business.”

Although Alonso grew up in Florida and Morgan in Ohio, they visited often enough that they became close -- “pretty much like brothers,” as Alonso put it. Throughout this season, as Alonso established himself as one of the game’s top power hitters, he dropped hints that if MLB invited him to participate in the Home Run Derby, he would ask Morgan to throw to him.

The invitation finally came in late June. Alonso quickly paid it forward to Morgan, an operations manager at an express detail car wash in Ohio.

“Both of us grew up around the game of baseball,” Alonso said. “We just love the game so much. We’re family. We grew up together. It’s just a really awesome opportunity because … my mom’s side of the family is all from Ohio. It’s kind of like a homecoming.

“Everything aligned perfectly. It’s in Cleveland this year, and having pretty much a bunch of family from there, I just think it’s a perfect scenario. He’s got that nice, short arm slot. He’s going to be coming in with a nice, big window. He’s going to be laying it in there. It’s going to be fun.”

Although Morgan mainly played middle infield during his high school baseball career, he pitched from time to time. He and Alonso have another connection, as well: both come from families with a military background, a fact that is coloring Alonso’s Derby participation. If he wins, he has pledged to donate 5% of the $1 million grand prize to the Wounded Warrior Project and another 5% to Tunnel to Towers, a Staten Island-based non-profit that aids first responders and their families.

“Both of us, I think we have a really, really important stress on the people who take care of human life, and are selfless in that regard,” Alonso said. “They put themselves in the line of duty, whether that be overseas or here, trying to protect us civilians in New York and around our country. I have the utmost respect for those people who are in the line of duty every day, that risk their lives to protect others.”