Most Instriguing Prospects at Instructional League

Instructional League, held at the St. Louis Cardinals training facility in Jupiter, Fla. from late September to early October, can represent a turning point in a prospect’s career. It’s a time when a handful of chosen players convene in a spring-training-like environment to practice all the little things farm director Gary LaRocque and his staff think they need to work on. It’s also when coaches get their mitts on newly drafted players, who are generally left alone in their debut seasons to show what they can do.

Now that this year’s Instructional League is over, we take a look at the players who stand to benefit the most from what they just learned and practiced in Florida.

Magneuris Sierra, OF (Johnson City/Peoria)

Credit: Bret Jacomet/Johnson City Cardinals

Signed out the Dominican Republic in 2012 for a mere $105,000, Sierra may go down in Cardinals lore as the organization’s best Latin signing ever. Hyperbole perhaps, but the 19-year-old outfielder has the goods. In 2014, his first in the States, he led the Gulf Coast League in hits (78) and batting average (.386), and the Cardinals named him the Minor League Player of the Year.

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The late Oscar Taveras is the only other graduate of the Cardinals’ Dominican Academy to do that, and Sierra seems to be on a similar developmental path. Sierra sprays the ball to all fields and has more discipline than most other players his age. He also has better wheels than Taveras did, which is why Sierra profiles as a centerfielder.

Then again, his rocket arm means he could be a nice fit in rightfield, too. If he can adjust his flat swing to get some loft on the ball, he could blossom into a power hitting corner outfielder. He’s already shown he can handle adversity. The Cardinals were encouraged enough by his breakout 2014 to start Sierra in low-A Peoria this year, but he struggled against pitchers who could consistently locate their breaking balls.

On June 9, hitting just .179, the Cards sent him to rookie-level Johnson City, where he got his groove back (.315 BA and .371 OBP) and was named an Appalachian League All-Star. So relax, Cardinal Nation. Sierra is back on track and learning to hit those breaking balls with authority at instructs this fall.

Edmundo Sosa, SS (Johnson City)

Credit: Bret Jacomet/Johnson City Cardinals

2012 was a very good year for the Cardinals on the international market. Not only did they land Sierra. They got top overall prospect Alex Reyes and Sosa, too. And like Sierra, Sosa’s calling card so far has been an advanced plate approach. He’s shown he can use the whole field and has the patience to wait for good pitches to hit. Young, 19-year-old just don’t do that, and the Cards have two of them.

Sosa joined Sierra in Johnson City this summer, and the former hit .300 while playing solid defense at short. The issue with Sosa is his speed. He’s got it. He just doesn’t use it well on the basepaths. The 5-11, 170-lb. Panamanian has stolen 21 bases in his three seasons in the system, but he’s also been caught 12 times. Not only does he need to run more, he needs to learn how to read pitchers so he can get better jumps. Guess what kind of drills he’s doing a lot of in Jupiter right now?

Ronnie Williams, RHP (Johnson City)

Credit: Bret Jacomet/Johnson City Cardinals

This isn’t Williams’ first instructional league rodeo. Probably won’t be his last, either. The 19-year-old righthander has a big arm but a raw feel for pitching. In high school in Miami and during his pro debut in the Gulf Coast League, he simply blew his mid-90s fastball by everyone.

A second-round pick of the Cardinals in 2014, Williams reported to Johnson City this summer and hung in there mostly because he was able to constistently locate the fastball in the lower half of the strike zone. He finished the season with 43 strikeouts and a 1.25 WHIP in 56 innings of work. Oh, he walked 25 hitters, too. If he’s going to have any prayer of sticking as a starter moving forward, Williams will have to bring along his curveball and changeup. He’ll be throwing those pitches almost exclusively in his similated instructional league games.