And that's why the culmination of landing him was so exciting for the Red Sox, who plan on putting the 27-year-old Castillo in center field.
"We've gotten a chance to get to know Rusney a lot over the last several weeks," said Red Sox general manager Ben Cherington. "And then before that, we had seen him play first in Amsterdam in 2011 and then again in Taiwan in 2012 and of course over the last several weeks, since he's been in Florida, we've gotten a chance to know him even better."
The Red Sox don't know exactly when Castillo will first don No. 38 in front of the Boston fans at Fenway Park. There's a work visa to complete first, and perhaps some Minor League games to play in.
But they expect it will be at some point before the 2014 season ends.
"This is an exciting player," said Cherington. "He's got a great combination of skills, defensive ability, speed, solid power. He's got a really strong track record in Cuba. We're excited to add him to the organization, and we feel he can be a part of winning Red Sox teams here for a long time."
Being able to formalize the $72.5 million pact at a news conference also marked the end of quite an odyssey for Castillo, who has long burned with the desire to play in the Major Leagues and follow in the footsteps of countrymen like new teammate Yoenis Cespedes, White Sox slugger Jose Abreu, Dodgers star Yasiel Puig and dominant Reds closer Aroldis Chapman.
"It's really a dream come true to have been given this opportunity to play, especially in light of the success of recent Cuban players. It's an honor and a privilege, really," Castillo said through an interpreter. "It really means a great deal, especially to have been able to sign with the Boston Red Sox who paid such close attention and have always treated me marvelously, actually, from the get-go."
Cherington credited two front-office lieutenants in particular for the inroads the club made with Castillo prior to the signing.
"Allard Baird and Jared Banner, who are both principal parts of our player-personnel group, really specifically focused on these markets, including Cuba, and have spent a lot of time getting to know Rusney and putting us in a position to consider doing something like that," said Cherington.
Though the Red Sox signed Castillo to a record-setting contract for an amateur international player, Cherington was on the edge of his seat until Friday, when he finally knew for sure his team had won.
When exactly did Cherington know he had his man?
"Not until we came to a verbal agreement and started looking at flights. There were obviously a number of teams involved," said Cherington. "I felt like it was very competitive but a very professional process. We felt like -- and I can only speak for the Red Sox -- we felt like we were given every opportunity to make the offers we felt like we needed to make, and we felt like we had a good sense for what we needed to do to sign him.
"We wanted to sign him, obviously, and ultimately we felt good about the outcome. But I didn't feel like we were going to be able to sign him until we were getting a flight for him."
And after Saturday's news conference, Castillo was right back on another flight to Miami, where he will pack his belongings and soon head to Fort Myers, Fla., to get his legs under him at the Red Sox's Spring Training facility.
After his initial attempt to defect from Cuba was unsuccessful, Castillo was suspended from game action in his homeland. He hasn't played a baseball game in roughly a year and a half.
But as was evident by his appearance at Saturday's news conference, Castillo has kept himself in top shape.
"To me, at this point, it's not so much about the time missed," said Castillo. "Because even though I have missed a year and a half of games, I've been training every day and to me, that's what's gotten me most prepared on a day-to-day basis. That's what we're going to continue to do moving forward."
The contract Castillo signed includes the remainder of this season, and it will expire following the 2020 season.
Castillo got a $5.4 million signing bonus and will earn $100,000 for the rest of 2014. He will earn $10.5 million in each of the next three seasons.
After making $11 million in both 2018 and '19, Castillo's final season of the contract would pay him $13.5 million. However, there is a clause in his contract that allows Castillo to opt out of the seventh year and become a free agent.
Castillo hit .319 (403-for-1,265) with 75 doubles, 11 triples, 51 home runs, 99 walks, 256 runs scored, and 76 stolen bases in 360 games over five seasons in Cuba's Major League, Serie Nacional. He played all five seasons for his hometown team, Ciego de Avila, and posted a career .383 on-base percentage, .516 slugging percentage and .899 OPS while playing mostly center and right field.
"We've had several scouts see him over a number of years and built some history that way," said Cherington. "You can recognize the bat speed, the swing path, the power, the ball comes off his bat really well, etc. and we have spent quite a bit of time sort of mining whatever data is available to us out of Cuba, performance data, and we feel like we are getting more and more precise in our ability to sort of translate that and figure out what it means."