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2019 BYB Tigers Prospect #29: SS Sergio Alcantara is still the best defensive infielder in the system

The shortstop has been pegged as one of the premium defenders in the system since the day he arrived.

New York Mets v Detroit Tigers Photo by Mark Cunningham/MLB Photos via Getty Images

It’s an oft-repeated lament that a team of the best defenders to ever grace a baseball field could be assembled of guys who never played in the major leagues. Exaggeration or not (it likely is), it’s a poignant observation on the fate of one-dimensional ballplayers. Often, it’s simply not enough to cut the mustard, particularly in an era where power at the plate rules the day.

When the Tigers acquired Sergio Alcantara back in 2017, they were hoping to unlock a side of his offensive side game that hadn’t shown itself before. Unfortunately, things haven’t improved substantially since the Tigers sprung for him two years ago. While he’s a defensive whiz, Alcantara’s glove is nearly negated by his almost complete lack of power.


Signed all the way back in 2012 as a 16-year-old from the Dominican Republic, Alcantara played his way into prospect status in 2016 and has fought his way up the ladder over the course of seven minor league seasons. He spent the first part of his career in the Arizona Diamondbacks’ system before being included as a secondary piece in the much-reviled J.D. Martinez swap.

While Alcantara has not done very much to improve his standing with evaluators in the two years since the trade, he may be higher on this list if he weren’t overshadowed by stronger infield prospects like Isaac Paredes, Wenceel Perez, or Willi Castro. Him coming in nine spots lower in the midseason rankings than the preseason edition of this list can largely be attributed to failing to impress on his logjam-induced repeat tour of Double-A [Ed.: And the addition of a new draft class].


Alcantara is a defensively sound shortstop. His skills should be more than sufficient to keep him at the position at any level of competition. Checking all the boxes, he can run down balls from long distances away and displays the instincts and defensive motions at the point of play to project as plus. Blessed with more than just excellent glovework, he also has a veritable rifle for an arm, which makes his defensive package playable at any position on the dirt.

Although the desperate situation with his bat will limit Alcantara to a utility role at most — we’ll address that in more detail later — he has the skills to carve out a place as the 25th man on a major league bench. Relegating a player to a utility projection is usually the kiss of death. In this case, it’s equally testament to just how gifted he is as a defender.

While his lockdown defense is undoubtedly his biggest strength, Alcantara has also shown some unexpected improvement at the plate. Routinely posting unusually high ball-in-play rates throughout his career, he’s not much of a free swinger either. This season, though, his plate discipline seems to have taken a step forward. A declining strikeout rate is encouraging, but that change is small enough that it looks a lot like statistical fuzz. Far more noteworthy is the steep increase of walks.

Alcantara’s walk rate in 2019 is 51.7 percent higher than his last tour of Double-A. At 263 plate appearances, it looks like we’re dealing with a legit change of some sort. It been said for years that in order to make an impact in the higher levels, the slight infielder would have to get some kind of meaningful improvement under his belt. Whether this accomplishes enough to move the needle on his future remains to be seen.


Anemic power drags Alcantara down to the low levels of the midseason rankings. Standing at only 5’9 and weighing in at 170 pounds, he will never be a power hitter. His swing isn’t geared for it, he doesn’t sell out his approach for it; he simply doesn’t have any power. At one point in time, that wouldn’t matter so much for a slam-dunk shortstop, but the game has evolved to prioritize offensive output.

There’s little chance Alcantara ever mends this glaring flaw either. He would have to sell out his approach in order to take harder rips at pitches, reversing the improvement he has made in that department. The slight frame that enables him to be such a nimble defender is another major factor in the equation. He can’t grow through sheer willpower. Small stature isn’t a complete death knell, but players like Jose Altuve who small and can hit are the extreme exception.

There’s not much else to put in the ‘cons’ section, but unfortunately, bottom-of-the-barrel power simply doesn’t play in the majors. Alcantara’s glovework and rocket arm may get him to the majors in some role, but it seems likely that this particularly knotty issue will hold him back from being a significant contributor.


Everything about this profile screams “Dixon Machado, Round Two.” While I generally find player comparisons a sloppy and ineffective method of writing about prospects, it seems that Alcantara has a very similar outlook as did Machado. If he sees time in the majors, it will either be as a utility guy filling in on a moderately competitive roster or low-end regular shoehorned onto a losing team.