This is why father and son are attached at the hip. They're the same person.
"It's been that way since he was born," Brandon said. "My wife will tell you the same thing. We're always together.
"Jayden makes it really easy to be a dad, because, really, he's just like me, wants to be just like me, and he really cherishes the time we get together."
Especially when that time is spent at the park, where dad works and Jayden plays.
Brandon, who has finally found a home in the Major Leagues at first base in Oakland, lets his 3-year-old son roam around the clubhouse often, knowing he may not always have the chance to expose his children to the unique life he's leading in a baseball uniform. Jayden soaks it all in.
"I think that when he comes in here, he really enjoys it and relishes it," Brandon said. "He's not the typical kid that comes in and is overwhelmed by it. He comes in and takes in everything. He loves the guys. He loves to go to the cage. He loves every bit of life, that's for sure."
And the chocolate milk in the A's clubhouse. Ice cream, too, if he's lucky to snag some after night games well after his bedtime. Josh Reddick is his buddy, and he was recently convinced that Seth Smith is his other dad, as he told Brandon in a grocery store the other day.
Brandon has to tell him, 'No, son, but he can be your friend.'
Brandon, 29, has found his best friend in Jayden, who got a baby brother, Brody, in April. He says he always wanted kids, even begging wife Allie, his high school sweetheart in Georgia, for one when he was just 23. Allie, 21 at the time, had the forethought to know to wait until their lives had some sense of stability.
They got just that, or as much as any ballplayer can have, in 2009, when Brandon played his first full season in the Majors with Pittsburgh. Jayden was born in October and, five months later, Brandon was designated for assignment. He ended up spending the bulk of the year with Triple-A Indianapolis.
The 2011 campaign brought about much of the same, except in a different organization. Brandon spent that season with Philadelphia's Triple-A affiliate, finding himself in Scranton, Penn., one night with Jayden resting on his chest.
"He was radiating heat," Brandon recalled. "His eyes were open, but he wasn't responsive."
Jayden was having a seizure, ultimately revealed as a symptom of Periodic Fever Syndrome, which includes recurrent episodes of fevers that he would get every month to the day. Doctors still don't have a clear understanding of why kids develop such an illness.
"Allie would circle the day, and he'd have it for maybe three days," Brandon said. "It could spike up to 105, 106. It got up to 106.9 one time. Luckily most kids grow out of it."
Fortunately, Jayden did after a year, but not before many scares, including tests for lymphoma and leukemia.
Brandon was in Pawtucket, Mass., when Allie mentioned leukemia over the phone. For the first time, the usually outgoing Moss didn't know what to say, so he went to a local mall and "just stood there forever," he remembers.
"I was thinking, 'How do I get my son through this? How do I get us through this? And what if something happens? You just have to put all those scenarios in your head.
"Finally I called her back and said, 'Whatever it is, it's already that.' There's nothing we did and there's nothing we can do to fix it. You just have to pray and you just have to hope and accept that whatever happens is what's meant to be. Whatever it is, we gotta enjoy him, make his life worth something. That was a hard conversation to have, because you're afraid you're going to lose him. He's my everything."
It was at that point Moss realized that the uncontrollable parts of parenthood are what make it scary. No matter how much he wants to, he can't protect his sons from everything.
"That was a really hard time," he said. "That's the hardest time I've had as a parent."
Once Jayden's fevers left, "it's been awesome since," Brandon says.
Each morning he wakes, Jayden asks dad if it's an off-day. When it is, they race to the yard to play some ball. Jayden loves to pitch, if only to watch sweet-swinging Brandon hit. In the offseason they go to the cages often so Jayden can show off his own swing to the other guys. Other days are spent at Chuck E. Cheese, or riding four-wheelers and tagging along with Brandon while going shopping.
It's the best job Brandon will ever have, no matter the uniform he wears.
"I love being a dad," he said. "It's hard to put into words, how it feels and how much I love it, but it's definitely what I enjoy most.
"Our kids will always know that home isn't necessarily a place, but that it's where family is."