KISSIMMEE, Fla. - Passing on the family calling may be one of Jason Castro's most rebellious acts.

The 26-year-old All-Star catcher once considered becoming a firefighter, just like his father and grandfather. Castro's only sibling, older brother Ryan, followed in their footsteps instead.

Arguably last season's most valuable Astro, Castro is a product of a close-knit family. He grew up in an aptly named area in Northern California just south of Oakland - California's Castro Valley.

The 6-3 lefthanded hitter always plowed straight ahead toward baseball. He played basketball until giving it up as a high school senior to focus on the sport that this winter earned him a $2.45 million contract for 2014. He hit 18 home runs with a .276 average last year.

Castro had a social life in high school, but even on Saturday nights, he would go to the batting cage before going out with friends.

Castro's father, Tom, still serves as his batting-practice pitcher every winter.

"I swore if I had a penny for every ball I threw at him, I'd be doing pretty good," Tom said.

Jason went home this offseason to finish his undergraduate degree at Stanford, where not one person recognized him. On his workout days, Jason and his father would drive together.

Tom first would drop Jason at the athlete performance center not far from campus, at a facility where Jeremy Lin of the Rockets also has trained. Tom, who's now coaching high school baseball after 30 years as a firefighter, would go get a cup of coffee and read the paper. When Jason finished, they'd head over to campus and hit and hit and hit.

Home improvement

That's how it was when Jason was a kid, too, as long as Tom wasn't working 24-hour shifts. He bought Jason a soft-toss machine, which they put in the garage so the younger Castro could always swing.

"You could load like 40, 50 baseballs into it and flip a switch and it would flip baseballs up to you automatically," Tom said.

And while the makeshift indoor batting cage helped young Jason's development, the same can't be said of his parents' garage.

"I'd come home from the firehouse and I'd have new holes," Tom said. "I remember a couple times, I chewed him out for that. And then I realized, 'You know what, go ahead. We can fix the holes later, keep taking your swings.' That's how he was. He worked hard - he worked harder than anybody. It's his work ethic."

At a field near home, Tom would throw to Jason while his mother, Lori, would snag balls. Lori, however, grew reluctant after stumbling on a snake in the weeds.

Losing a 'mentor'

He would also talk baseball with his paternal grandfather, for whom the sport was always special. The elder Castro, also a firefighter for 28 years, pitched and had a chance to play professionally, but his career was curbed by an arm injury.

"He lived 10 minutes away growing up," Jason said. "He was always kind of a mentor and always giving us advice. Not just about baseball, but life, and everything. He was definitely a big influence on my life."

On Feb. 8, two weeks ago Saturday, Jason's grandfather died of cancer at age 83.

Ready to build on a budding career, Jason arrived at spring training with a heavy heart.

"It was tough," Jason said. "It was definitely tough. Especially having services and everything right before coming out here."

Castro is entering a crossroads phase of his baseball career.

Several times this winter, he was the subject of trade rumors. He was the team's top pick in the 2008 draft - No. 10 overall - but whether he's around long enough to play alongside more recent top picks, like shortstop Carlos Correa, is anyone's guess.

For now, Castro is a cornerstone of the Astros. In a different market on a winning team, he'd already be a household name. Will he stick around to become one in Houston?

Extinguish distractions

Like the other Castro men, Jason knows how to put out a fire.

"I think my friends and family reacted more than I did," he said of the trade speculation. "Those things are probably going to happen from time to time in a given career. It's not something you really need to focus your energy on, and it actually was kind of nice - I was back in school so I had a pretty full workload, and that was kind of a distraction (from the rumors).

"I've been here since the beginning of this process. It's starting to come to fruition now a little bit. You can definitely see the light at the end of the tunnel. I think we're a lot closer than people think. … Obviously, to be a part of that, to see it all the way through to the other side would be pretty rewarding."

The Astros and Castro did not discuss an extension this winter. There's no set time when they will, either.

General manager Jeff Luhnow didn't draft Castro. He was still in the Cardinals' front office at the time.

"The consensus was that it was an aggressive draft," Luhnow said. "I wouldn't call it an over-draft, but an aggressive draft given where the Astros were picking that year. But the reality is, if you draft a catcher in the first round … and he hits 20-plus home runs, that's a very good first-round pick. And so the Astros were very justified in making that selection.

"Any one of our young players, you can rest assured, at some point we will have, at a minimum, conversations internally about (an extension). You can rest assured we have had those conversations internally about Jason."

Castro's breakout 2013 was in part due to a change in his swing path the prior winter. Most of his life, he had a swing that went down and across, and he had trouble going the other way.

Health not a concern

With the help of a hitting coach named Craig Wallenbrock - and after that, Astros hitting coach John Mallee - Castro developed and maintained an improved technique. It's second-nature now, he said.

"It was like a light switch in the batting cage prior to spring training," he said. "I really made it a goal of mine in the offseason to readjust that and make sure I was as long through the zone as possible and make sure I was finishing high."

But he can't hit if he's hurt, of course.

Castro has had knee troubles in the past, including at the end of last season. Those are particularly scary for catchers, whose job is to squat. Castro started working out early this offseason - he's been through tougher rehabs before - and said he feels 100 percent.

"They're all individual incidents," Castro said of the knee ailments. "And the funny thing is that the knee injuries that I have sustained are from baserunning. They're not even catcher-related. The first one (in 2011) was in spring training, stepping wrong on a base, and the one last year I kind of stepped wrong on a base as well."

Focused on the frame

There's another question surrounding Castro that, less than a decade ago, likely wouldn't have come up.

The framing of pitches by catchers has become all the rage. It's the skill of making pitches technically out of the strike zone look like strikes to an umpire - and the skill of also ensuring that pitches that should be called strikes in fact are.

Mike Fast's title in the Astros' front office is inconspicuous: "analyst, baseball development." But he has a degree in physics and was a pioneer in the world of pitch data, and he's a central figure behind the scenes.

Fast meets with coaches more often than players, but he met with Castro last week in Florida, and the two talked about framing, a part of his game in which Castro has plenty of room to grow.

Around 6:30 in the morning this spring, Castro and the other catchers get to work on receiving in the batting cage.

"It's a little bit of everything," Castro said. "It has to do with where you set up, how you set up, how you receive balls … It's something that's always kind of been intuitive and just something that was kind of done."

A family man at heart

With time and repetition, Castro can improve. He's always had work ethic, from the flip machine in the garage to Stanford this winter. His father said Castro always has had an ability to separate his work from his life, too.

Castro married his wife, Maris, a fellow athlete at Stanford, about a year ago. They have a dog. They're foodies who love to travel.

So what if Castro is traded some day?

His widowed grandmother, Pearl, will still be able to watch him on TV.

"My aunt lives right next door to my grandma," Castro said. "She has a pretty good support system.

"In the offseasons the last few years, I'd go back to California and just stop by and grab some lunch and just go over and hang out with my grandparents and talk.

"They were always watching (games) on the computer. They watched all my games. My grandpa would call me whenever I hit a home run."