SF Giants pitching prospects week in review (8/22-8/28)

Make sure to revisit our weekly SF Giants prospect rundowns to keep up with each of the organization’s minor-league affiliates. If you do not feel well acclimated to the prospects throughout the farm system, you might want to revisit our prospect week articles that detailed the system from the top prospects to lower-level fringes. If you’re just interested in the biggest names, then the preseason SF Giants top 31 prospects list is the one-stop-shop for you.

SF Giants Prospects Weekly Rundown: Triple-A

Notable Performers

Kervin Castro: 1 G, 2 IP, 1 H, 0 R, 1 BB, 3 K, 0.00 ERA
Camilo Doval: 2 G, 1.1 IP, 2 H, 0 R, 0 BB, 3 K, 0.00 ERA
Sean Hjelle: 1 G, 1 GS, 5 IP, 10 H, 5 R (5 ER), 3 BB, 2 K, 9.00 ERA

What a roll Kervin Castro is on this season for the River Cats. The 22-year old is pitching to the tune of 1.20 ERA in his last eight appearances with a 20 to 5 strikeout to walk ratio in 15 innings of work. There seems to be a pattern of work for Castro all season as he is pitching every fourth or fifth day and has pitched at least two innings of work in 10 of his last 13 appearances with a 2.08 ERA and has only allowed a .191 opponent’s batting average. While he is pitching very well, the next thing for Castro is pitching effectively with fewer days of rest.

After struggling for most of this season, Camilo Doval has found his groove this August with seven scoreless outings in both Sacramento and San Francisco. He has not allowed a walk in his last six outings and has a nice 69% strike rate over that stretch with 11 strikeouts in 6.1 innings of work. Hopefully, this is the start of things trending in the right direction for Doval.

Sean Hjelle‘s start to his Sacramento career has been rough. The 2018 second-rounder has a 6.23 ERA in his three starts for the River Cats with almost twice as many walks as strikeouts (9 walks vs. 5 strikeouts) in 17.1 innings. Upon watching his starts, Hjelle has a little problem throwing over the strike zone but is failing at executing his pitches and his stuff is getting timed by minor league veterans quickly. He’s nibbling instead of attacking hitters even though his mid-90s fastball velocity should be enough to get outs.

SF Giants Prospects Weekly Rundown: Double-A

Notable Performers

Michael Plassmeyer: 1 G, 1 GS, 0.2 IP, 6 H, 4 R (4 ER), 1 BB, 2 K, 54.00 ERA
Matt Frisbee: 1 G, 1 GS, 5 IP, 5 H, 3 R (3 ER), 1 HBP, 1 BB, 3 K, 5.40 ERA
Luis Amaya: 2 G, 4 IP, 3 H, 1 R (1 ER), 0 BB, 5 K, 2.25 ERA
Joey Marciano: 2 G, 3 IP, 1 H, 0 R, 0 BB, 1 K, 0.00 ERA

With Sean Hjelle promoted to Richmond and Caleb Kilian traded to the Cubs, there is a big void that exists at the top of the rotation for the Flying Squirrels that coaches hope Michael Plassmeyer can fill up. In his last three starts, however, Plassmeyer has been rocked for an 8.31 ERA in 13 innings of work. He struck out 18 hitters and only walked four but the big issue is the loud contact that he gave up with 21 hits and five home runs within the stretch. The left-hander now has a 4.73 ERA but is vastly split in his home-road splits with a 6.00 ERA on the road but a 2.06 ERA at home.

The Giants are also hopeful that returnee Matt Frisbee could fill up the void. His three starts since coming back are not particularly positive, however, with a 4.96 ERA. There is nothing particularly problematic with Frisbee’s peripherals as he is still throwing strikes at an above-average rate at 67%. The problem is the vast increase in terms of the loud contact that he gave up, particularly home runs.

A couple of left-handers were effective this week. Both Luis Amaya and Joey Marciano were lights out this week after struggling a bit the previous week. Amaya is on a roll in his last six outings with a 2.31 ERA in 11.2 innings pitched with a 16:3 strikeout to walk ratio. Marciano, on the other hand, has slightly fallen off the rails after a superb start to his 2021 season with a 4.91 ERA in his last 21 appearances and was a heavy victim of the BABIP gods with a .348 rate. Both Amaya and Marciano could see time in Sacramento next season.

SF Giants Prospects Weekly Rundown: Low-A

Notable Performers

Kyle Harrison: 1 G, 1 GS, 5 IP, 5 H, 1 R (1 ER), 1 BB, 9 K, 1.80 ERA
Nick Swiney: 1 G, 1 GS, 3 IP, 2 H, 0 R, 1 BB, 7 K, 0.00 ERA
Randy Rodriguez: 2 G, 1 W, 3 IP, 2 H, 0 R, 1 BB, 7 K, 0.00 ERA
Prelander Berroa: 2 G, 2 GS, 11 IP, 7 H, 6 R (5 ER), 1 HBP, 5 BB, 12 K, 4.09 ERA

Even though the Giants have looked after his pitch load in recent weeks, Kyle Harrison was as good as ever in his latest start with five innings of one-run ball and nine strikeouts. Known for generating a high whiff rate, Harrison has his best month ERA-wise in August with a 2.33 ERA and 33 strikeouts in just 19.1 innings pitched. The nine walks and six hit batters are however on-brand for Harrison’s sometimes erratic control, but he is generally in the strike zone more often than not.

Nick Swiney had another stellar start this week as he continues to pile up the innings after missing a good chunk of the season with a concussion. Swiney is on a 50-pitch limit but he is making up for the lost time. His latest start against Lake Elsinore was vintage Swiney as he got the Storm hitters off-balanced by junk balling them with curveball and changeups that drew out 11 swings and misses. The changeup consistently flashed plus while the control of his curveball was decent even though it flashed above-average. Due to how advanced Swiney is and how many reps he missed due to injury, there is a possibility that he will be pitching in the Arizona Fall League.

After being named the Low-A West Pitcher of the Week, the first San Jose reliever to win the award this season, Randy Rodriguez continued his stellar month with two more dominant outings this week. If Rodriguez made his final appearance of the month last night, it will cap off what was potentially one of the most dominant months I have seen from a reliever all season long, with 15.2 innings of shutout baseball allowing only nine hits with a 27:3 strikeout to walk ratio. He looks electric on the mound with great athleticism, lightning-quick arm speed, mid-90s fastball, and a hard slider. Rodriguez has a shot to win the Pitcher of the Month with his performance.

Prelander Berroa had a tough August with a 4.84 ERA but the most concerning thing is his strike-throwing having only thrown 58% of his pitches for strikes compared to July where he threw 64% of his pitches for strikes. He allowed 14 walks in 22.1 innings pitched. His latest start, however, was reminiscent of Berroa’s dominant July except for a home run he allowed on a hanging slider. Even though Berroa’s numbers looked rough this month, I like how he tried to use his slider as a chase pitch a bit more often.

SF Giants Prospects Weekly Rundown: Rookie

Notable Performers

Sonny Vargas: 1 G, 1 GS, 1 W, 6 IP, 1 H, 1 R (1 ER), 1 BB, 9 K, 1.50 ERA
Esmerlin Vinicio: 1 G, 1 GS, 4 IP, 4 H, 1 R (1 ER), 1 HBP, 1 BB, 5 K, 2.25 ERA
Trevor McDonald: 2 G, 2 GS, 8.2 IP, 7 H, 4 R (4 ER), 3 HBP, 6 BB, 15 K, 4.15 ERA
Mikell Manzano: 2 G, 1 GS, 1 W, 7.1 IP, 3 H, 2 R (1 ER), 0 BB, 10 K, 1.23 ERA

Four of the top five pitchers that lead the Arizona League in strikeouts are from Giants affiliates. The pitcher who leads the way with 57 strikeouts is left-hander Sonny Vargas. His start to his season was awful with a 9.64 ERA in July but was much better in August with a 2.84 ERA across five starts and a 33:4 strikeout to walk ratio in 25.1 innings pitched. The 20-year old from Venezuela has improved his frame as he matures and has a high arm slot. His 5.60 ERA is tough to look at but his strong peripherals make him a pitcher to follow.

Second in strikeouts with 56 is Esmerlin Vinicio. Vinicio has been usurped by Manuel Mercedes as the top Giants pitching prospect from the 2019 international free agent class but it has not stopped Vinicio from posting solid numbers in Rookie ball with a 2.35 ERA. Vinicio is still super wiry that I do not project to gain a good amount of muscle as he matures but Vinicio throws strikes, has a good baseball IQ, and could be fit in the Nick Swiney mold of junk balling hitters with strong secondaries alleviating his lower fastball velocity.

The third with 55 strikeouts is Trevor McDonald. “Effectively wild” is the best term to describe McDonald’s 2021 with 27 walks allowed and nine hit batters in 51 innings pitched. Based on the new footage that I have seen, McDonald flashes above-average to plus with his slider and his fastball is highly effective at the top of the zone due to the funk in his mechanics and a low 3/4 arm slot. However, his feel for the strike zone is below-average and his command is worse. Nonetheless, McDonald is an uncomfortable at-bat.

One of the more impressive pitching prospects in the Giants’ Dominican complex is Mikell Manzano. Even though it is easy to not trust the statistics in Rookie ball, Manzano is often talked as one of the standout pitchers in the Felipe Alou Academy. If there is one thing that we can trust is his control. Out of 102 batters that Manzano has faced this season, he has only walked one. A feat like that is incredible in its own. I am excited to see what he can do when he hits Stateside.

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