A second-round pick in 2015 out of high school in Texas, Santillan struggled during his first two years as a pro but turned the corner in 2017 and was the organization’s Minor League Pitcher of the Year in ’18. The 2019 season was a step backward, however, as the right-hander was less effective and had command issues that doubled his walks rate from the previous year.
There were a few things that may have contributed to Santillan’s regression. A new pitching philosophy was installed organization-wide from new Major League pitching coach Derek Johnson that required some adjustment. Observers noticed that Santillan tried to do too much on the mound while relying less on the great power stuff that got him one step from the big leagues. His velocity -- which normally can reach 97 mph -- also dipped, likely because of a triceps strain that put him on the injured list in July. While his changeup and slider are still developing, he’s still a good athlete despite his large size and can field his position well.
The 2020 season will be a big year for Santillan, who still projects as a member of a big league rotation. He needs to get back to what worked for him before 2019, but given that he’ll turn just 23 near the start of the 2020 season, there’s still plenty of time for him to figure it out.
Scouting grades: Fastball: 70 | Slider: 55 | Changeup: 55 | Control: 50 | Overall: 50
A large-sized, power-armed pitcher taken in the second round out of the Texas high school ranks in 2015, Santillan struggled over his first two professional seasons but turned the corner in 2017 and made many improvements in 2018 with his best year yet en route to being named the organization's Minor League pitcher of the year.
Scouts believe Santillan can be a frontline starter. He possesses a well above-average fastball that stays consistently at 93-97 mph with good movement, even deep into his starts. His secondary pitches are also becoming formidable, with scouts particularly noticing a huge improvement in his changeup. Although it can be a plus pitch, Santillan needs to continue developing his slider's consistency. Command and control were areas where Santillan needed to improve entering last season and he often succeeded as his walk rate dropped from 2017 to '18.
Already a big guy when drafted, he's gotten even bigger and thicker since to access more power while remaining durable. After he spent a half-season at Double-A a year ago, he is getting closer to putting it all together to reach his ceiling.
Scouting grades: Fastball: 70 | Slider: 55 | Changeup: 55 | Control: 45 | Overall: 50
After watching Santillan pop up on Draft radars in 2015, the Reds took the hard-throwing Texas high school product in the second round of that June's Draft. His first taste of full-season ball, in 2016, didn't go so well, but he started figuring things out in 2017, taking the biggest step forward among the top arms at the lower levels of the Reds' system.
Santillan looked more like the future big league starter the Reds envisioned in 2017, finishing fifth in the organization in both ERA and strikeouts and among the Midwest League leaders in several pitching categories. Santillan's plus plus fastball will touch the upper-90s consistently with good movement and will always be his best pitch. The right-hander made huge strides with his changeup in 2017 to the point where it now looks like it will be an above-average pitch. His focus on his changeup did lead to him losing some usage of his slider, though the hard breaking ball still flashes plus.
Command and control will be the next things Santillan will have to improve on in order to make the next step. The big-bodied flame-thrower showed more stamina and durability in 2017. Now it's time for him to put it all together in order to reach his ceiling as a frontline starter.
Scouting grades: Fastball: 70 | Slider: 60 | Changeup: 45 | Control: 45 | Overall: 50
A two-way player from the Texas high school ranks, Santillan was a bit of a pop-up prospect heading into the 2015 Draft. The Reds loved his arm strength and grabbed him the second round and are pleased with the progress he's made during his first full season.
Santillan might have as big of stuff as anyone in the system. He'll throw his fastball in the 95-100 mph range and he combines it with a plus slider, and he misses bats with both of them. His changeup is still below average, but it has gotten a little better as he throws it more. He has struggled with finding the strike zone at times, largely because of mechanical issues, but he worked to clean up his delivery during the 2016 season and in instructs last fall. A big-bodied right-hander, Santillan is a decent athlete, but he does need to improve his stamina.
Santillan needs to keep working on harnessing his plus stuff over the course of a season while refining his command. If that happens, he could enter the conversation of some of the better right-handed pitching prospects in the game.
Scouting grades: Fastball: 70 | Curveball: 60 | Changeup: 40 | Control: 45 | Overall: 50
A two-way player from the Texas high school ranks, the Reds were able to sign Santillan from Texas Tech when they took him in the second round of the 2015 Draft. His electric arm and raw stuff give him as much upside as just about anyone in the system, though he has a long way to go in learning how to harness it.
Santillan has a tremendous repertoire at his disposal, starting with a plus fastball that has touched 98 mph and can sit in the 93-95 mph range. He can throw a true hammer curve in the mid-80s that also misses bats to give him a second above-average pitch, but he doesn't have much of a feel for a changeup yet. Santillan has a bit of a cross-fire delivery. When he's online, he's as good as anyone in the system, but he comes in and out of it, making it tougher for him to command the baseball.
A better athlete than you'd think given his size, Santillan should be able make the adjustments necessary to the mechanical flaws in his delivery so he can take full advantage of his stuff.
The most electric arm in the state of Texas for the 2015 Draft, Santillan didn't show a ton of feel for harnessing his stuff until late in the season. It was enough for the Reds to take him in the second round and sign him away from Texas Tech with a bonus slightly above pick value.
Santillan has a strong 6-foot-3, 240-pound frame and a very quick arm, and when he keeps his mechanics under control he looks like a future ace. Santillan can work at 93-95 mph fastball and hit 98, with some late life when he keeps it down in the zone. His curveball can be a true 12-to-6 hammer and reach the mid-80s.
The problem is that Santillan can't hold his delivery together, often flying open and overthrowing. That causes his fastball to straighten out and his curve to lose its shape, and prevents him from keeping either pitch near the strike zone. He has yet to show much aptitude for throwing a changeup.
