PORTLAND, Me.—It didn’t generate much attention at the time, but a youth tournament in the city of Lagos de Moreno in Mexico six years ago was filled with future major league talent.

It was October 2010 when scouts ventured to Mexico for the COPABE 16U Pan American Championship. At shortstop, the United States had Corey Seager, who finished second in the tournament in hitting, ranking behind only his double-play partner, second baseman Alex Bregman. The U.S. was strong up the middle, with Albert Almora in center field. Mexico’s ace was Roberto Osuna.

The player in Lagos de Moreno who captivated the attention of scouts was Cuba’s 15-year-old third baseman, Yoan Moncada. Despite being one of the youngest players in the tournament, Moncada showed dynamic athleticism, tools and feel for the game beyond his years. It was the first time Moncada had traveled out of Cuba, the first time international scouts had seen him play.

Ten months later, after hitting .500/.643/.918 with eight home runs and 37 walks in 158 plate appearances back home in Cuba’s 16U national youth league, where he led the league in nearly every offensive category, Moncada returned to Lagos de Moreno for the 16U World Cup, where he dominated again and made the tournament’s all-star team at third base.

“There’s a 16-year-old, Yoan Moncada,” said one international scout in 2012. “He’s the best player down there (in Cuba). He’s a switch-hitting third baseman with five tools. He’s the guy—and everyone who’s been scouting Cuba knows it.”

Since then, Moncada left Cuba and signed with the Red Sox in March 2015 for $31.5 million, with the Red Sox paying a total of $63 million including the 100 percent overage tax to the commissioner’s office for exceeding their international bonus pool.

Moncada has so far lived up to the hype. Between high Class A Salem and Double-A Portland, Moncada hit .294/.407/.511 in 491 plate appearances with 15 home runs, 45 stolen bases and 72 walks. At 21 years old, Moncada was the Futures Game MVP, the No. 1 prospect in baseball and is now a big leaguer, forcing his way to Boston.

For that, Moncada is Baseball America’s Minor League Player of the Year. Yet as talented as Moncada is and as productive as he’s been already, the most tantalizing part is how much better he still has a chance to become.

Power And Speed

During Moncada’s time with the Red Sox, the one part of his game that stood out from the start was his speed. Moncada is a 70 runner on the 20-80 scouting scale. While it would be understandable if it took Moncada time to understand the nuances of stealing bases, that hasn’t been the case. In 81 games last year with low Class A Greenville, Moncada stole 49 bases in 52 attempts, a 94-percent success rate. This season in the minors, Moncada was successful in 79 percent of his stolen base attempts, with 45 steals (tied for fifth in the minors) in 57 tries.

“If you talk to him about baserunning, you can be amazed by how much he knows about stealing,” said Carlos Febles, Moncada’s manager this season in Double-A Portland. “He knows exactly what he’s looking for. He knows the time he’s looking for. He takes a lot of consideration into how the catcher is throwing the baseball and how quick the pitcher is to the plate. He knows exactly when to run and when not to run. He sits on the bench trying to pick up something on the pitcher every night. Even when he’s not playing, he’s always trying to pick up something, in case we face that guy and he gets on so he knows exactly what to look for.”

Moncada doesn’t look like your typical speedster—he’s built for power. He has the legs of a running back, the back of a Ninja Turtle and the explosive bat speed few others on the planet can match.

“He’s got big power,” Febles said. “When he hits it, it’s very impressive. Something he does well is that he doesn’t try to hit balls out of the park during BP. He’s a guy who knows exactly what he needs to do when it comes down to getting ready for the game. If you watch him take BP, he tries to go the other way, stay on top of the baseball and stay through the baseball. He knows that if he does that consistently, in the game, once you get the head out, the ball’s going to go out of the park.”

Except, early on, Moncada wasn’t showing much over-the-fence power in games. Before Moncada signed, there were scouts predicting he could hit 30 home runs in his prime. But in 81 games last year, Moncada hit eight home runs. This season in 61 games in Salem, Moncada hit four homers.

The bat speed, the strength and the raw power were still there, and he showed it in flashes by shooting lasers over the fence to the opposite field and launching balls off the batter’s eye in center field. However, Moncada had a habit of prematurely cutting off the follow-through when he finished his swing, slamming on the brakes rather than continuing to drive all the way through his swing.

“It’s just a matter of him getting extension through the baseball,” Portland hitting coach Jon Nunnally said. “He would cut some of his swings off and it would just get a lot of topspin, so the ball just wasn’t carrying. But once he started getting through the baseball for a little bit more extension, the back side and everything would get through, the ball just started jumping off his bat.”

In mid-June, after Moncada arrived in Portland—a home park that suppresses run scoring and home runs—his power spiked, with 11 home runs in 45 games with the Sea Dogs. Moncada was already a productive hitter and a line-drive machine with a compact swing (more so from the left side than the right), but the Red Sox wanted to optimize his stroke to capitalize on his raw power.

“It helps him drive the ball more, to where, when he hits something hard, it really goes, instead of it dying on him because he’s topspinning the ball,” Nunnally said. “Some people can topspin them and they’ve got a lot of power, which he does, it’s just that, he hits a lot of line drives. So for hitting those line drives, if he doesn’t get through it properly, it’s going to die. He hits them hard, but it’s just getting over the infielders as opposed to him getting good extension through the baseball so he can maximize that constant, continuous carry.”

When Moncada jumped to Double-A, so did his strikeout rate, rising from 21 percent in high Class A to 31 percent in Double-A. Moncada can smoke anyone’s fastball, but in Double-A, pitchers started to attack him with more offspeed pitches early in the count and behind in the count. In particular, the changeup—a pitch Moncada didn’t see often in Cuba, where pitchers often throw splitters instead of changeups—gave him problems. Facing the Padres on Sept. 6 in his fourth major league game, Moncada saw just four fastballs in 18 pitches and went 0-for-3 with three strikeouts.

Yet while Moncada’s offspeed pitch recognition will need to improve, he does show good plate discipline. He’s an aggressive hitter who’s ready to hit the first pitch, but he lays off close pitches off the edges of the plate even with two strikes, drawing a walk in 15 percent of his minor league plate appearances in 2016.

“Even though he’s had a lot of strikeouts here, this is a guy who has a pretty good eye,” Febles said. “You don’t see him chase pitches out of the zone.”

Defensive Ability

Moncada has the most room for growth in the field. When he airs it out, his arm is a 70 on the 20-80 scouting scale. He has the hands, athleticism, body control and quickness to develop into an above-average defender, whether it’s at second base (where he has spent most of his time with the Red Sox) or at third, where he moved over to play last month.

The biggest criticisms of Moncada in the field right now are the types of things more often heard about young, athletic shortstops. They make the flashy, acrobatic play, but make careless errors that stem from focus, fundamentals or questionable decision-making, like when to hold on to the ball rather than try to make the incredible throw.

“I think at second base he’s a guy who has plus range,” Febles said. “His first-step quickness at second base is amazing, how quickly he can get to the baseball and how quickly he can get rid of it to turn double plays. To me, the main thing was to keep him under control. The guy has so much talent and is so fast that, sometimes, he was going a little too fast. In this game, you have to be aggressive but, at the same time, you have to be under control. I was very impressed with the way he was playing second base. As a former second baseman, I was like, wow, I’ve never seen a guy with that first step, how quickly he was getting to the baseball and how quickly he could get rid of it.”

When Robinson Cano came up through the minors, his defense was a constant question mark. That didn’t change during his rookie year as a 22-year-old with the Yankees in 2005, with Baseball-Reference.com pegging him with -22 fielding runs that year. But Cano revamped himself into an above-average defender and win multiple Gold Glove awards. Moncada, a better runner and athlete than Cano, could have the same type of defensive transformation.

Now, though, with Dustin Pedroia locked in at second base and a hole at third base, the Red Sox moved Moncada over to third, a position he last played when he was 16.

“It’s not hard at all,” Moncada said in Spanish through a translator. “Whatever you learn, you never forget. It’s still there—like riding a bike. The difference is, there’s more movement at second base. At third base, it’s more about agility and reactions.”

The early returns have been encouraging. Moncada is still getting acclimated to the angles, but in limited time he’s already made terrific plays with his range to both sides and charging in on slow rollers.

That’s what makes Moncada such an exciting player. He’s already proven himself to be one of the most productive players in the minors. If everything clicks, Moncada could develop into a Gold Glove defender, an on-base machine with the power to hit 30 homers and speed to steal 40 bases.

As good as he is right now, Moncada is just beginning to tap into his potential.