Toolshed: Prospects on the upswing

Call these the grind times.
Baseball players talk a lot about dealing with the grind of a long season, something that can be felt most in July. The weather's hot; the pennant chase is not quite here yet; the games within games -- adjusting to another team and then adjusting to their adjustments -- have played out. There are roughly six weeks left in the Minor League season, and any number of reasons why performance might hit a lull for young players.
Yet that's what makes it so much more impressive when young stars get hot around now -- and even more so for those who struggled early on. This Toolshed covers those who got off to slow starts but are potentially changing the narratives around their 2019s. (Note: prospects covered here are all ranked within the top 10 in their farm system, according to MLB.com, and all stats are through Monday's games.)

Marlins 2B Isan Díaz, Triple-A New Orleans: The Marlins' No. 6 prospect ended last season in the Pacific Coast League but hit just .203/.281/.358 in 36 games there. Things didn't get much better in his return this April with a .645 OPS and only two homers in 24 contests. Since then, he's been put up an OPS above 1.000 in each month since. In fact, in July alone, he has a slash line of .351/.422/.702 with six homers through 14 games. Overall, Diaz is hitting .305/.394/.586 with 24 homers (fifth-most in the PCL) in 92 games with the Baby Cakes. Of course, this comes with all of the caveats involving the use of the Major League ball in Triple-A this season and the power jump across the Minors' highest level. But it's still notable to see the 5-foot-10 left-handed slugger stand out so much of late among his peers, who are using the same ball. Diaz should push for a spot in the Miami infield by the end of the season, especially considering the down years of Starlin Castro and Martin Prado.

Royals RHP Brady Singer, Double-A Northwest Arkansas: Singer's season as a whole actually got off to a promising start. The 2018 first-rounder posted a 1.87 ERA with 53 strikeouts in 57 2/3 innings at Class A Advanced Wilmington, prompting a promotion on May 30. Then, he was humbled in the Texas League fairly quickly. The 6-foot-5 right-hander gave up 15 earned runs over his first 16 2/3 innings for the Naturals, giving him an 8.10 ERA through his first four starts. What's more, he walked as many batters (eight) as he struck out in that span. Singer seems to have found his groove of late, however, with three straight quality starts for a 1.89 ERA, 20 strikeouts and five walks over 19 innings. The top Royals prospect has the plus fastball and plus slider to make things work at Double-A; he just needed the experience to put things together. Further development of his changeup will determine how much he can improve his 4.53 ERA the rest of the way.
Orioles OF Ryan McKenna, Double-A Bowie: The Orioles' No. 7 prospect has been on a bit of a roller coaster the last 15 months or so. He hit .377 with a 1.023 OPS over 67 games to begin 2018 at Class A Advanced Frederick, only to see those fall to .239 and .670 over 60 games in the second half at Bowie. He moved to the Arizona Fall League and was a star there with a .344/.474/.590 line, 10 extra-base hits and 14 walks in 17 games. McKenna was unable to carry that production back to the Eastern League and entered July with just a .227/.304/.359 line. He's been much better since this latest flip of the calendar; in fact, he collected multiple hits in nine of his 19 games this month and entered Tuesday with a .343/.432/.614 line and 11 extra-base hits in July alone. The 22-year-old center fielder can provide value with his plus speed (18 steals in 2019), and his glove certainly works in center, meaning he has value even when he doesn't hit. But it's positive all the same that his offensive pendulum is swinging in a positive direction.
Phillies OF Mickey Moniak, Double-A Reading: This may be weird to say, but it's a little unfortunate that Moniak was the No. 1 overall pick in 2016 because of the weight of expectations that comes with such a designation. Now at Double-A in his age-21 season (when others his age are being drafted as college juniors), Moniak is putting together his best offensive year yet as a pro, and that comes even after he hit .195 with a .611 OPS over 19 games in April. Since May 1, the left-handed-hitting outfielder owns a .293/.359/.467 line with three homers, eight triples and 17 doubles over 66 games. His .826 OPS is ninth-best in the Eastern League over that span. What's more, he's had little trouble returning from a hamstring injury that held him out for 10 days earlier this month with a .297/.381/.514 line and a 4/5 K/BB ratio since returning from the IL on July 11. Lest anyone think these numbers from a career .260 hitter are aided by Reading's hitter-friendly confines, Moniak actually has a higher slugging percentage on the road (.467) than at home (.428) this season. There still isn't a heck of a lot of power in the bat, but Moniak is showing enough improvements with his overall hit tool to point his arrow back in the positive direction. 

Braves LHP Joey Wentz, Double-A Mississippi: Control, control, control. That's what it's going to come down to for the Braves' No. 9 prospect in his first turn at Double-A. After his outing on June 20, Wentz owned a 5.51 ERA, in part because he had walked 10.7 percent of the batters he had faced through 14 outings (67 innings). In the month since, he has a 1.67 ERA with 40 strikeouts over 32 1/3 innings -- that K total representing the second-highest mark in Double-A since his start on June 26. More importantly, Wentz dropped his walk rate to 9.6 percent and has seen his free-pass total drop in each of his last five starts to the point where he gave up just one over a season-high eight innings Sunday against Pensacola. The 21-year-old has three above-average pitches in his fastball, curve and change; he just needed the control to turn those offerings into swings and misses. With a stronger finish, Wentz will improve his case to join Atlanta's rotation at some point in 2020.

Twins SS Royce Lewis, Class A Advanced Fort Myers: This has felt like a long time coming for the No. 7 overall prospect. Lewis has talked this season about trying to push too hard for a move to Double-A, and that mind-set may have caused him to make too many adjustments early on. As such, the 20-year-old shortstop, who produced an .803 OPS during his first full season in 2018, was hitting just .229/.276/.350 entering July. He has turned things around in the season's fourth month, hitting .316/.403/.474 with two homers and three doubles through 14 games. That's the first time he's hit above .300 or slugged above .450 in any month yet. The important thing to remember about development is that it isn't always linear -- prospects can take as much away from their failures as they can their successes. If Lewis is finding his way back to the mechanics and swing that allowed him to take off in his first full season last summer, then this year's tribulations won't be for naught.

Pirates SS Oneil Cruz, Class A Advanced Bradenton: The first half of the season was one to forget for the Pirates' No. 4 prospect, though not from a performance standpoint. Cruz missed time in April with a lower-body injury and then was officially placed on the injured list with a right-foot fracture on April 28. He finally returned to the Marauders lineup on June 30 and looks determined to keep this from being a lost campaign. The 6-foot-6, left-handed-hitting shortstop has produced a .348/.364/.580 line with four homers and four doubles over 17 games since coming off the IL. His 40 total bases are the most in the pitcher-friendly FSL in that time, while his .946 OPS is second only to teammate Cal Mitchell's 1.047. Power has always been Cruz's offensive calling card, but it was up in the air how long it would take for that tool to return coming off the injury. He could be a candidate for the Arizona Fall League to make up for some lost time starting in September, and it should be fun to see if the bat plays even better once it's out of the FSL.

Marlins OF Connor Scott, Class A Clinton: The Marlins need as many player-development success stories as they can get, and Scott's recent turnaround could possibly be placed into that column. The 2018 first-rounder was flirting with the Mendoza line as late as June 22, when he had a .213/.274/.330 line through 64 games. Only 13 players in the Midwest League had a lower OPS than Scott's .602 at that point in the season. He's been a completely different hitter since then, batting .366/.418/.505 in his last 25 games with a .923 OPS that is sixth-best in the MWL over that time. Entering Tuesday's off-day for Clinton, he had a 13-game hitting streak, during which he was batting .444. Scott's biggest value comes in his speed and defensive qualities, so he wasn't exactly expected to fly out of the gate in his first full season. But this latest run could salvage the perception of his overall hit tool heading into his second offseason. The next goal could be to add power; Scott last went deep on June 10, though he does have five doubles in his last five games.