(You can find the primer on the 20-80 grading scale here)
Potential, potential, potential. Here are few comps that I've heard associated with Magneuris Sierra this offseason:
The size of the gap between the expectations from those player profiles seems to be about as wide as the Mississippi is long. But that's to be expected from a guy with just 52 games stateside at age 18. Obviously choosy kids choose the Gonzalez and Ellsbury comps (with Jif and without all the injuries, preferably), but even Parra and Pagan are useful big league players to have cost-controlled for 2/3 of a decade. Especially at a $105,000 initial signing bonus.
How do you pronounce his name? I'll turn it over to Brian Walton of The Cardinal Nation blog since he's one of the few out there in the blogosphere that's spoken with Sierra 1-on-1:
Not that most will remember or perhaps care, but #stlcards OF Magneuris Sierra told me that he pronounces his first name "mahg-nair-EE".
The only video of Sierra is a shaky-cam special courtesy of Birdland's Derrick Goold last August:
A couple of things to note from this PA:
This setup is typical of what I see from a lot of young Dominican players: Open stance, back elbow up, hands high up near the ear.
Sierra's hands have a "hitch" in them during the load phase: They drop first, then load, then start the forward motion towards the ball. This is something that will probably need to be ironed out of his swing at some point in the future. Even in this PA you can see Sierra is a bit late on most of the fastball's he sees. Most likely, he'll just need to lower his hands from the starting position (so he no longer has to drop them first) or he could just adjust by loading his hands without dropping them first (although that has it's own set of problems too)
The bat is very quick and the swing has some real raw power (which could grow to plus as he gets stronger and irons out his load phase). You can see how strong his hands and wrists are on a couple of these swings when he fouls off a couple of pitches and holds up on another.
Regarding his wicked slash line, I have two things to point out. One is the fact that 54.3% of the balls Sierra put in play per minorleaguecentral.com were on the ground (grains of salt please, many grains of salt). The other is that his batting average on balls in play was .444. That's a circle not likely to continue to be squared as field conditions, defenses, and players get better in the upper minors, not to mention that amount of luck required to do that at any level. He hits a bunch of line drives too, hits the ball hard everywhere he puts it in play, and has great speed, but still -- there's just no way that will continue so expect some hard regression in 2015.
So who is the former Cardinal prospect that Sierra reminds me of?
Oscar Taveras, of course.
The similarities are striking: Both from the Dominican, both jumped onto prospect lists in their age 18 season (Taveras debuted at #8 on John Sickels' Top 20 Cardinals list after his Johnson City season in 2010, Sierra debuts this year at #9). Neither were highly thought of as teenagers, neither got huge signing bonuses, both started hitting the moment they set foot in the United States. Both, of course, are left handed.
The tools are a little different. Sierra isn't as big as Oscar was and won't likely ever have Taveras' plus raw power either. What he lacks in those he makes up for defensively and with his plus speed. Also keep in mind that Taveras at age 18 was a scrawny dude -- he didn't start to bulk up into the slugger body type until around age 20.
I'm not saying that Sierra will ever be the prospect that Taveras was. That's highly unlikely. But his ceiling is every bit as high given the tools here and Sierra might top this list as soon as next year depending on how hard the club wants to push him.
If Sierra continues to follow in Taveras' footsteps, a jump to full season ball would be in order in 2015. The farm system, however, is in much better shape from a depth perspective than it was in 2011, so there's certainly some time to be patient if the club feels it is warranted. Given the hitch in his swing and his luck on balls in play in 2014, perhaps extended spring training followed by a short season stint with State College would actually be best for Sierra's overall development. So far, the player development group inside the organization seem to have a good read on when players are ready to move up a level, so whatever decision they make has a good chance of being the right one.