When the Royals dealt left-hander Jake Diekman to the Oakland Athletics last July, the return appeared to be underwhelming. At the time, Diekman was Kansas City’s top reliever, striking out 13.6 hitters per nine with an upper 90’s fastball and wipeout slider. But the Royals were unable to net a top-30 prospect from Oakland’s farm system. Instead, they received 26-year-old outfielder Dairon Blanco and 20-year-old pitcher Ismael Aquino. Blanco, who is highly touted for his 80-grade speed, was signed out of Cuba in 2018 and spent all of 2019 in Double-A. Between Midland and Northwest Arkansas, he slashed .262/.325/.419 with 12 triples and 27 stolen bases.
Aquino, on the other hand, was an unpolished arm with raw potential. He debuted with the Athletics’ rookie ball team in 2017 at 18-years-old, posting an ERA of 3.13 in 46 innings with 44 strikeouts. However, he walked 44 with five hit batters and four wild pitches. In 2018, he managed to make the jump from Rookie ball to Triple-A for one outing, but walked four of the eight batters he faced and gave up two runs. Before he was shipped over to the Royals’ system in last half of the 2019 season, Aquino spent more time throwing out of the bullpen than starting. Despite starting 21 career games heading into the season, the right-hander started just one of the 18 games he appeared in 2019.
The 20-year-old struggled when he joined the Arizona League Royals, giving up 14 runs on 16 hits in 11 innings. Though his season ended on a lower note, the Royals organization had spent time working on a few of Aquino’s secondary pitches. According to his Fangraphs report, Aquino had toyed with a cutter when he pitched in the Oakland system, but had it scrapped a month or two before the trade. Once he joined Kansas City’s organization, he brought it back into his repertoire. Aquino managed to bump the velocity on his cutter from the low 80s (80-82 mph) to mid-to-upper 80s (85-88-mph) before the end of the season.
His best pitch is his fastball, which sits anywhere from 93-97 mph with a max of 98. It grades out as a 60/65 but lacks consistent command and results in his high walk numbers. Not only is his shaky command lead to walking over five hitters per nine innings, but when he misses, opponents are squaring him up. Batters are hitting .424 on balls in play with a line drive percentage of 17.1%.
The Royals, however, do have value in the 21-year-old. His spin rate of 2300 on his fastball ranks above top arms Kris Bubic, Brady Singer, Jonathan Bowlan, Jackson Kowar, and Daniel Tillo. His future value of 40 labels him a backend starter with a WAR between 0.0-0.9 and the 31st best prospect in the organization. Among other pitchers, Aquino ranks in the top 15 in terms of FV.
Perhaps what is working against Aquino is his age at the Rookie Ball level, as the righty will turn 22 in September. Unless he can harness his fastball and develop a strong cutter, it will be difficult for Aquino to surpass High-A. The upside, however, is that the Dominican Republic native has tossed only 109.1 innings in his professional career, giving him plenty of time to settle in a roll and mature over time. After all, it appears that he could be shifting into a relief role if 2019 is any indication of how 2020 will progress.
There’s still time for Aquino to mold himself into a starter, but he’ll need to get himself to A-ball at some point during this season. That promotion relies solely on his command and if that cutter begins to develop. His Fangraphs report tells it all.
“Aquino is a young relief prospect whose profile is driven by arm strength. He’ll sit 93-97 and occasionally fool a hitter with his circle change, but everything else about him lacks consistency.”
His arm strength alone will give him the edge on potential and keep the Royals’ organization believing he can mature. However, Aquino doesn’t want them to think he can, he wants to prove it.