MESA, Ariz. -- Owen Caissie took a break from his round of hitting at the Fieldhouse Pirates' facility and answered a phone call. The outfield prospect had a brief conversation and then returned to the batting cage.

"We all asked him, 'Hey, what's going on?'" said Jimmy Richardson, the director of baseball operations for the Fieldhouse Pirates in Burlington, Ont., in Canada. Caissie told the group on hand that the Padres had just given him some news.

"He's like, 'Oh, they just told me I got traded to the Cubs,'" Richardson continued. "He's like, 'All right, let's go back [to hitting] off the machine.' It didn't faze him at all."

Richardson said it was a moment that summed up one aspect of Caissie's personality. It was December 2020 and the Cubs had just completed the blockbuster trade that sent Yu Darvish to San Diego. Yes, Caissie's baseball life changed -- just not in that specific moment. The kid still had work to do in the cage.

Knowing the news was about to spread swiftly among his family and friends, Caissie turned off all his social media and other phone notifications so he could remain focused. And then he completed his workout before allowing himself to absorb all that was to come.

"It was kind of surreal at the moment," Caissie said.

It is easy to forget that Caissie is still just 19 years old when engaging in conversation with the Cubs' No. 9 prospect (per MLB Pipeline). The imposing 6-foot-4 outfielder, who has tufts of bright red hair bursting from beneath his cap, is well-versed in the nuances of his swing, approach and the data associated with both.

Caissie certainly showed his potential last year, when he hit .302 with a .923 OPS in 54 games between the Arizona Complex League and Low-A Myrtle Beach. Before his promotion in August, the young slugger hit at a .349 clip with a 1.074 OPS in 32 Rookie-level games.

"We all raked," Caissie said of the group of prospects the Cubs had in the ACL last summer.

As an amateur hitter, Caissie loved to study video of Major League hitters to find things he could try with his own swing. These days, when he is armed with a wealth of information and technology, he has actually decided to take a step back to concentrate more on feel, as opposed to overloading himself with analytics.

"I still use video every day," Caissie said. "I look at my swing. But when I look at it, it's, what am I feeling? I put my swing and what my thoughts are together and that's how I kind of [plan] my attack every day."

"Owen wants a lot of information," said Justin Stone, the Cubs' director of hitting. "He's one of those guys we're trying to make it less analytical and more see-and-react. He's done a really good job with that."

It is the kind of mature, professional approach that Richardson witnessed within Caissie from a young age.

Caissie began taking hitting lessons with Richardson at the age of 11 and joined the Fieldhouse program by the following year. The lefty-swinging kid was tall and lanky and it took plenty of time and practice for his coordination to meet the potential of his swing.

"You would see it. There were always moments where it would click," Richardson said. "He'd take 10 or 15 swings and two or three of them, you'd say, 'Man, this guy's got it.'"

By the age of 15, Richardson said Caissie's work ethic reached another level. Caissie was showing up seven days per week, and returning after a quick trip home for dinner. He began developing a routine to work on his own, establishing a tee program and making sure purpose was paired with volume.

As Caissie neared his eligibility year for the MLB Draft, "he turned into an animal," Richardson said.

That lanky kid searching for coordination was now featuring a natural swing with development power, and his physical abilities were taking off with the work done in the weight room. The only problem was pitchers started refusing to pitch to him.

"I think I averaged like two walks a game at one point," Caissie said with a laugh. "It was good for on-base percentage, but not good for the scouts, because they wanted to see me swing."

There were multiple times Caissie was even walked with the bases loaded.

"Yeah, a bunch," he said. "If you look at the odds, I'm going to get out more times than I'm going to get a hit, so I didn't really understand it. But, it is what it is."

Caissie's coaches told him he might want to consider expanding his zone a little bit with the scouts in the stands. He obliged and started putting on an offensive show.

In 2019, Caissie was selected for the Tournament 12 showcase for Canada's top amateur prospects at Rogers Centre in Toronto. During the home run derby, he slugged 11 shots in the final round to win the event. That, for Richardson, was the moment Caissie put his competitiveness on full display.

"He just refused to be beat," Richardson said. "It was like, 'I'm going to show everybody here that I can put balls out of a big league stadium.' And he just put on an absolute show. It was just jaw-dropping."

On March 12, 2020, while playing for the Canadian junior national team, Caissie took righty Connor Overton deep at TD Ballpark in Dunedin, Fla. It was shortly before the pandemic halted the season -- robbing Caissie of time to try to convince evaluators he was worthy of a first-round pick.

The Padres grabbed him in the second round in '20 with the 45th overall pick. That was six selections ahead of the Cubs, who had hosted Caissie for a pre-Draft workout at Wrigley Field.

Eventually, the Cubs found a way to bring him into the fold as one of the potential pieces to the future core.

"He got traded for Yu Darvish," Richardson said. "A lot of guys might take that and put some more pressure on their shoulders. He's just like, 'Back to work.'"