Zack Collins, C, Chicago White Sox (High-A Winston-Salem)
Collins may be one of the pickiest hitters in the minors right now, as evidenced by his.212/.384/.379 slash line. At the plate, Collins is an extremely patient hitter with above-average plate discipline and pitch recognition. He has a mild bat wrap, but it doesn’t seem to impede his balanced, smooth swing. There’s unquestionably plus power in the bat. Right now, though, too many of Collins’ deep counts are ending with strikeouts, and he’s pounding plenty of balls into the ground with a low-line drive rate to go along with it. He has to work on making consistent contact more often.

Behind the plate, Collins seems like a logical game caller; he has soft hands and can handle balls in the dirt well. He’s not afraid to be a bit frisky either; I saw him throw behind a runner at second early in game action and behind a runner at third later in the evening, with above-average release and accuracy. He’s been more consistent with his pop times and throws velocity-wise this season, and the numbers back that up. The book on Collins in 2016 was that you could run on him, but he has certainly changed that perception in 2017. In a diverse and interesting White Sox system, Collins is certainly a name to watch.There is tangible progress in his defense that could go a ways towards combatting a pre-season scouting consensus that he was unlikely to last at the position. —Victor Filoromo

Jesus Luzardo, LHP, Washington Nationals (GCL Nats)

On the deserts of the Mets minor league complex, where players have no name and games have little fanfare, I witnessed this athletic, 6-foot-1, 200-pound lefty. He averaged a 92 mph fastball with moderate sink, packaging it with three other promising pitches: a 79-81 mph, 1-7 curve with shape and bite; a 81-84 mph slider with good depth and tilt, and a convincing drop change with a speed differential of approximately 15 mph! Though admittedly his stuff isn’t quite what it was pre-surgery, it was his first start of the season and a step in the right direction. He placed his pitches where he wanted to and, like a veteran car salesman, he sold them with conviction and minimal flags. In awe of this unrecognizable figure, one of the opposing pitchers publicly and quizzically noted, "Who is this lefty pitcher, sitting 93 and barely missing his spots?". I responded (to myself) "Well, my son, his name is Jesus Luzardo, and this is his Second Coming." —Javier Barragan

Isan Diaz, SS, Milwaukee Brewers (High-A Carolina)
On a team studded with top-five-round talent, Diaz stood out during Saturday’s double header. He tracked spin easily at the plate, and only swung and missed at two pitches on the day. Diaz not only has a plan at the plate, but is short to the ball and makes solid contact when he does swing. He didn’t showcase his power in this showing but he faced exclusively lefties (including an advanced Keegan Akin), where it appeared his approach was hard contact up the middle. He’s traditionally muscled up against right-handers in his career and scouts I’ve talked to have put a plus power grade on Diaz’s swing.

He can struggle with his internal clock in the field, and botched a read on a slow grounder, opting to wait on it and then rush the throw—resulting in a bobble and no play—rather than charge it. These reads won’t be so difficult at the keystone, where he’ll be afforded more time on most plays, and where his athleticism could result in a plus defensive profile. —Craig Goldstein

Bryan Reynolds, CF, San Francisco Giants (High-A San Jose)
Reynolds certainly looks the part, with a tall, toned frame that stands out amongst his peers. He is a lo-fi player who goes about his business with the urgency of a blade of grass growing, meticulously settling himself into the box. Once in there his personality carries over into his at-bats, where the approach is one of patient aggression: he waded pretty deep into at-bats, but he didn’t do so with an intent to take a walk. There are pros and cons to the swing: he’s vertical and passive at load, with a high back elbow, late hitch into a mild bat wrap, and a lack of lower-half torque that limits his ability to generate consistent timing with his weight transfer. The result, at least in these at-bats, was an arms-and-hands swing that depended on out-front extension to succeed. And while he showed bat speed and quickness into the zone relative to the swing path’s length, he forced himself into the kind of earlier commitments that could threaten his bat-to-ball skills further up the chain.

The glove didn’t yield a ton on first impression. There’s a steadiness and evident thought process behind his breaks and routes, but his foot speed is more average than asset, and he lacked the kind of second-gear into the gap that I typically look for in a center field prospect. Still, I didn’t see much in the way of clear deficit to the game, and that’s certainly a good starting point for any prospect. —Wilson Karaman

Antonio Santillan, RHP, Cincinnati Reds (Low-A Dayton)

The knock on Santillan since being drafted in the second round (49th overall) has been his lack of command. The Reds believe that their player development staff can simplify the delivery and make it more repeatable, harnessing the potentially electric stuff that Santillan possesses. Still young, just turning 20 this month, he is physically mature, with a thick build. He works out of a semi-windup with a three-quarters arm slot delivery, and shows above-average arm speed. In my look, the fastball sat 92-93 and touched 95 several times with some arm-side run, which kept hitters from barrelling it up. The gas was paired with a 12-6 curveball that shows plus potential but is still a work in progress.There were a few occasions where the breaking ball lost shape and flattened out, but when Santillan got it right it showed good bite and hitters had a hard time laying off the 84-86 mph curve. There were a few changeups sprinkled in, all which sat 81-82 and none of which showed much movement. Overall, Santillan has a major-league caliber arm but the command needs to continue to improve for him to advance to that level. —Nathan Graham

Jairo Labourt, LHP, Detroit Tigers (High-A Lakeland)
Labourt's stock is skyrocketing. After failing as a starter, struggling with command, control, and lacking the athleticism to field, the Tigers have decided to make him a reliever and are receiving immediate dividends. Though it is his third season opening in High-A, it’s his first as a reliever, he’s taken to it well, producing 19 strikeouts against three walks and one earned run in 11 â…” innings. On Wednesday night against Port St. Lucie, Labourt demonstrated a 95-97 mph heater, which either cut like a hot knife through butter or tailed like a loose car tire, and paired it with an often back-footed slider at 87-90. He toyed with a firm 87-90 mph changeup that had tepid movement—an ugly reminder to his yester-years as a starter. That reminder aside, as a reliever you need to command at least two pitches, and he did that with his fastball and slider, both of which registered plus.

It could be as simple as catching his best outing. Or it could be that this is a start of something new. Or it could just be a hot start for a reliever, and the regression is coming. I mean, it is April, and yes, small sample size. Nonetheless, for this single outing, Labourt showed an ability to command and repeat his delivery with plus pitches. As for Labourt's development plan as a starter? I hope it is at the bottom of the recycling bin. —Javier Barragan

Scott Kingery, 2B, Philadelphia Phillies (Double-A Reading)
Stop me if you’ve heard this one before, but FirstEnergy Stadium in Reading may be inflating some offensive numbers. But hold on! Kingery is hitting well away from FirstEnergy Stadium, too. Color me interested. Kingery was the Phillies’ second-round pick in the 2015 draft out of the University of Arizona, and is enjoying a breakout 2017 at the age of 23. He played well in High-A Clearwater last year but the bat wasn’t there when he was promoted to Reading late in 2016.

This year has been quite different. Kingery is barreling balls more consistently and using above-average bat speed and raw athleticism to make necessary adjustments at the plate. He’s a plus runner and capable of making all the routine plays in the field. He seemed like he was going down the path of a low-risk, fringe-average regular as of the end of last year, but now seems like he has a chance to make that next leap into being an average regular if this pace keeps up. —Victor Filoromo

Ian Happ, 2B/OF, Chicago Cubs (Triple-A Iowa)
Happ, a switch-hitting second baseman/outfielder may end up pushing his way to Chicago sooner than later, especially if you believe in the power he is showing early on in 2017. Happ employs are pretty decent sized leg kick and uses it effectively for timing. As the pitch is released Happ gets to the top of his leg lift ensuring he never has to be rushed in his sequence. While the swing starts slow and calm. it doesn't end that way. He does a good job of getting his lower half cleared and creating good angles with the upper body, giving himself room to work behind the ball and generate plus bat speed that can drive the ball to all fields. These kinds of actions lend credence to the power numbers he’s managed so far in Triple-A and if they can stick, Happ will more than live up to his ninth-overall billing. —Derek Florko

Lucas Williams, 3B, Philadelphia Phillies (Low-A Lakewood)
A 2015 third-rounder out of a prep school in The OC (ed. note: don’t call it that), Williams is a welcome rarity for a Low-A third baseman: a prospect that can pick it at the position. Far too many A-ball third basemen are either not long-term third baseman or not prospects, but Williams shows excellent range coming in, side-to-side, and back on infield pops. An average arm limits the overall defensive projection at third to just plus, but I also suspect Williams could probably handle positions such as second and the outfield given his athleticism and above-average speed. He might have to, because he's been largely overmatched by minor-league pitching since being drafted. I like his swing some and he's got a decent enough approach for the level, but there's just a lack of physical strength there leading to his being overpowered at the plate currently. The hitting might yet come—he's only 20 and there's some projection left, to steal from BP terminology—and I'm going to keep an eye on him as the year progresses to see if he can start barreling enough to move forward. —Jarrett Seidler

Ryan Castellani, RHP, Colorado Rockies (Double-A Hartford)
It’s no secret that the Rockies have had a heckuva time trying to develop pitchers in their 25 years at Coors Field. But they have quietly developed quite the pitching pipeline this season. Kyle Freeland, Antonio Senzatela, and German Marquez have all contributed to a surprising April surge to the top of the NL West, and the Rockies still have an interesting arm or two at each of their full-season ball affiliates. Castellani is the best pitching prospect in their Eastern League hub. He works off a power sinker in the low-90s that also gets good arm-side run from his tick-below-three-quarters slot. He can spot it down to both sides of the plate and can cut it a bit at 89-90 as well. He offers a full four-pitch mix. The slider is the best current secondary. The command is inconsistent at present, and he usually deployed it as a big-breaking, glove-side chase pitch in the low 80s, but he also showed a firmer one with late two-plane break. The curve is slurvy and can bleed into the slider some, but it shows earlier and he mostly used it to spot a strike early in counts. The change could be pretty true, but the best showed sink and fade with a deceptive arm action and plenty of velocity separation at 83-85 mph.

Castellani’s delivery has some funk to it. There’s a long stride and a bit of hesitation before foot strike to let his arm catch up, but it doesn't negatively impact his command too much, and he is athletic enough to repeat it. It's easy to look at the lower slot and changeup development needed and cast him as a pen arm. Especially since this is a Double-A pitcher. He's only a theoretical phone call away. Senzatela made fewer than 10 starts in the Eastern League before the Rockies dumped him in their major league rotation. But Castellani is only 21, he still has plenty of time to refine, and I'd expect some additional physical development as well. Although I think he could help in the bullpen as soon as the second half of this year, there’s no need to make that move so soon. He does tick a few of my usual “future reliever” boxes, but something about watching him on the mound made me think he has better odds to make it as a starter than I'd usually give this profile. —Jeffrey Paternostro

Thank you for reading

This is a free article. If you enjoyed it, consider subscribing to Baseball Prospectus. Subscriptions support ongoing public baseball research and analysis in an increasingly proprietary environment.

Subscribe now
You need to be logged in to comment. Login or Subscribe
Jesus Luzardo may be the annual Nats prospect who gets brought up in every chat from July-on. Once he gets into short-season and pitches like Javier Barragan saw here, he will be popular. Two years ago it was Robles, last year it was Soto. If he's healthy, his stuff will garner a lot of interest.
Any thoughts on Eguy Rosario? Getting it going very well of late after a slow start in FW. Believe he is the youngest player in full season ball