"A lot of people may have thought I was emotionally stunted when I was playing," the 14-time MLB All-Star quipped to E! News' Francesca Amiker in an exclusive interview. "That's not the case, I just hid it well. But I think having kids brings out the softer side of everyone, and I couldn't be happier."
Once Derek called it a career in 2014 after 20 seasons and five World Series rings, he wasted little time setting up a true home base with his wife of now seven years, Hannah Jeter. Fast-forward to this summer, when they piled four children into their Jeep Grand Wagoneer for a road trip to the Baseball Hall of Fame festivities in Cooperstown, N.Y., and the couple can measure—in memories and mileage—how far they've come as a team.
"Just to clarify, it was her bright idea to bring all four of them," Derek cracked, pointing to the 2015 Sports Illustrated Swimsuit Issue cover model sitting next to him. "It was ambitious."
But Hannah simply refused to leave their youngest, then-2-month-old Kaius Green, behind.
And yes, the four-and-a-half hour drive from New York City was "definitely chaos," Hannah shared, with daughters Bella Rain, who's since turned 6, and Story Grey, 4, in boosters and River Rose, 21 months, and her baby brother in respective car seats.
"We need a lot of room," Hannah described the scene. "We need a big trunk. We need a good sound system, as Derek would say, to drown out the noise. You need a lot of snacks."
Hence the couple having an up-close-and-personal relationship with Jeep, especially now that they require that third row of seats. Having starred in the automaker's "Eyes Wide Open" campaign last year, they're returning Sept. 12 as the faces of "Drove All Night"—which is inspired by how much time they spend behind the wheel as parents and, Derek said, "really is authentic to who we have become."
They were at a Jeep event, the 49-year-old explained, and they had to excuse themselves so they could get home and be on the ball for their morning routine, which starts with taking their older girls to school.
"That's what we try every day," Derek added, sharing that he and Hannah do all the dropping off and picking up—and usually together.
But though his old morning routine of grabbing coffee and just driving around by himself is in the rearview mirror, the Fox Sports analyst has grown to love being surrounded.
While having a big family was the plan, it was admittedly "strange to even just see a boy, as opposed to the girls that I'm used to," Derek said of becoming a father to a son in May. But it's also decidedly "awesome."
"I was never a guy that said, 'Hey, I have to have a boy, I have to have a boy,'" said the athlete, whose bejeweled face at Bella's 6th birthday party in August showed he's still a quintessential girl dad. "Because, you know, I'm in love with my girls. But I'm so happy to now have a son."
Four-month-old Kaius is still pretty stationary at the moment, Derek added, "which is not a bad thing when you have to chase three others around." But he expects an uptick in the rolling over and sitting up action within the next few months, so there will be more updates from that arena in the future.
Meanwhile, Kaius' big sisters are loving the living doll in their midst. "We're trying to kind of keep them separated," Hannah said, "because he's still little and you don't want him to get the germs and all those funky viruses from school. But they're all over him. They're always kissing him" and seeing them interact is "pretty fun."
Now that school has started, the biggest change to their daily routine is earlier bed times—and, subsequently, earlier dance parties.
"They're performances," Derek said of their almost nightly tradition, of which he most definitely takes part. "It's very theatrical."
And although even his and Hannah's nights out tend to conclude in a we-need-to-get-home-so-we-can-get-up-early fashion, those dates are important to the duo's overall connection as husband and wife.
"We started having kids right after we got married," Hannah said, "so, [we] just continue to make time for each other, take trips. There's a lot going on, day-to-day, in our household—a lot of noise, a lot of kids—and that can be really overwhelming. So it's nice once in awhile, date night—just the simple things."
But since they only get so many moments alone, good times of all shapes and sizes are where the heart is.
"You just have to continue to have fun," Derek offered. "You have fun with each other, have fun with family, have fun with friends."
And at the end of the day, whether it's just the two of them or the backseat is full, he and Hannah are enjoying the ride.