After slow start, Yoan Moncada quickly got up to speed

Yoan Moncada’s base-stealing prowess — 49 thefts in 52 attempts — was one indication of his athletic talents.Richard Spiro for The Boston Globe/File 2015

GREENVILLE, S.C. — Whenever Yoan Moncada reached base, everyone on the field understood that he would be running at the earliest possible opportunity. Still, he couldn’t be stopped.

When the curtain lifted on the second half of the South Atlantic League season, the numbers piled up: two steals in the first game out of the All-Star break; two games later, another pair of bags, and then another the next day.

Second base? Third base? Didn’t matter. He would run.

Moncada, the 20-year-old second baseman who played for the Red Sox Single A affiliate in Greenville, stole 11 bases without being thrown out in the first 16 games of the second half. He stole multiple bases in 14 of 56 games after the break, eventually accumulating 45 steals (in 48 attempts) in a season-ending 56-game stretch, and 49 in 52 attempts on the season.

He reveled in the bases he did steal, while lamenting the fact that he didn’t seize earlier opportunities (while working through some early-season soreness in his legs) to get north of 50, 60, or even 100 — a mark that he suggested he could have achieved “easily.”

In many ways, it was on the bases that Moncada found the swagger befitting his prospect stature. But he also found something considerably more significant than that. Each opportunity to run represented a portal to a home and a family from which he is separated indefinitely.

“It’s been something since I’ve been a child — I love to bat, I love to field, but my favorite part is stealing bases,” Moncada said recently through translator Rut Rivera. “In Cuba I used to train with my father at the beach, over in the beach sand with a pair of boots that would cover my ankles.

“My dad would have me put the boots on, I would go in the water, wet them, and then run in the sand to do sprints two times a week. And then I would run in the field normally. That helped me a lot.

“My dad always told me that my strongest feature was to steal bases. My dad used to run, too. So I love running and stealing bases.”

Difficult adjustment

The steals served as part of a second half that in many ways validated the brimming talent that led the Red Sox to sign Moncada to a record-setting $31.5 million bonus, and an antidote to any early-forming clouds of doubt that arrived after his slow beginning in Greenville.

While the Sox’ commitment to him created an immediate expectation of dominance, it was easy to disregard the magnitude of his transition. Yet in retrospect, it’s clear that there were several reasons why he’d be challenged to excel, beyond the obvious pains of homesickness.

Moncada hadn’t played for a year since leaving Cuba to pursue a career in the major leagues. When he signed, he’d spent weeks as a showcase warrior bouncing between workouts for different teams, a strange and exhausting process that netted him a windfall but did little to prepare him for games.

Moreover, most of the players in Greenville had been in the Sox organization for at least one summer, and in many cases, parts of three or even four years. Moncada was trying to learn the terminology and routines of a new organization on the fly starting in March.

He’d never played with anything like the frequency that confronted him in Greenville, with his most recent playing experience having come in the 90-game regular season of Cuba’s Serie Nacional. The jump to seven games a week, with hours of pregame work under Greenville’s pounding sun, long bus rides, and minor league “sleep” schedules, required adaptation.

“He was a different animal,” said Greenville manager Darren Fenster. “I think a lot of people outside the organization and maybe even inside the organization had unrealistic expectations for this guy, but he hadn’t played in a long time.

“We have a specific way of doing things and a routine of doing things that this guy had no idea. We had to put that foundation in with him that everybody else already had. It was a much slower process out of the gate.”

It wasn’t just evaluators who wondered about Moncada’s performance when he stumbled to a .200 average, .287 OBP, and .289 slugging mark in his first 25 games of the season.

Moncada himself struggled to accept the unfamiliar results and the foreign sensation of being out of rhythm after a year spent without game-speed competition.

“At first, I felt uncomfortable and even a little angry with myself, and a little bit upset,” said Moncada. “But even my dad told me it was going to take a little bit to adjust. I was able to analyze everything mentally and physically. That’s when I started picking up.”

Switch to leadoff

It was over the four-day span between the end of the first half and the start of Greenville’s second half that Moncada had the opportunity to regroup.

The Red Sox facilitated that process by moving him from the No. 6 spot in the lineup, where he’d spent his first 25 games, up to the leadoff spot.

That suited Moncada, who had spent much of his career in Cuba batting leadoff. It was atop the order that Moncada said he felt “more comfortable, more free,” more easily connected to the talent that had defined him as one of the top young players in Cuba. It was atop the order that Moncada started to perform like that player as well.

He quickly erased the evidence of his slow start, posting a .310 average (tops among Sox full-season minor leaguers from June 25 through the end of the year), .415 OBP (second in the system), and .500 slugging mark (again, best among Sox prospects) with 7 homers after the break to finish the season with a .278 average, .380 OBP, and .438 slugging mark.

By the end of the year, his body of work was sufficiently impressive that managers, coaches, and scouts in the South Atlantic League named him the level’s Most Outstanding Prospect.

“He’s special,” said Greenville teammate Bryan Hudson. “He’s got things you can’t teach. He’s just a really talented person. I don’t even know how to describe it. He’s just a little bit different.”

In addition to his baserunning ability, Moncada also showed advanced plate discipline, the ability to hit rocket line drives, and clear big league defensive tools that suggest the possibility of being able to play at any number of positions down the road.

“This guy is as good an athlete as you’re going to see on a baseball field,” said Fenster. “Obviously other managers and coaches and scouts around the league have seen that as well.

“Early on, it was a struggle for him. But once he came into his own, he was able to put that athletic ability into tangible baseball skill, it was just different than everyone else.

“That’s why he’s getting the accolades that he is. They’re very warranted. At the same time, he’s got a long ways to go. He’s got major league tools, but he’s in the minor leagues for a reason. He’s got to consistently turn those tools into things that are going to produce.”

An eye on the majors

For Moncada, the recognition offered measures of reassurance and satisfaction.

“I found out through my agent. I didn’t know anything,” said Moncada. “I had people telling me congratulations. I was like, ‘Why?’ Then I saw an article, too, that talked about it.

“I felt very happy because it’s my first year here. I feel really good. I’m not all the way, 100 percent, but I feel really good with the things that I’ve been doing.”

Moncada suggests that there is more. He looks forward to resuming beach workouts this offseason, to get his legs in shape for the pounding of a full season. Recognition as a top prospect in Single A is a nice line on a résumé, but ultimately, it doesn’t fulfill any of his goals.

As the season wound down in Greenville, Moncada made it clear that he’s aiming high.

“I’m going to get prepared to play in any of the leagues they send me to, but definitely prepare to play in the major leagues,” said Moncada. “In my mind, I want to make it to the major leagues before I’m 22.

“I’m going to prepare myself and I’m going to do my training with the mind-set that I’m going to the major leagues next year. If the team lets me work with the major league team next spring training, I’ll do my best. If I’m able to reach the major leagues next year, that’s great.”

He may have the talent to do that. The foundation is being laid, the lessons from Greenville layered on top of the ones first instilled on the sandy shores of his native land.

There are more to come, of course, but for Moncada, the faltering first steps of walking into professional ball are now behind him. He’s eager for the opportunity to run forward.

“Slowly I started picking up and catching up to the system,” said Moncada. “I’ve felt great these last two months. I’ve felt great but I don’t feel that I’ve made it yet. There’s more to do.”