"He fits in to what we've been doing," Reds senior director of amateur scouting Chris Buckley said. "He's a very good athlete. He's a real big, strong guy that's a very good prospect as a position player."
• 11th overall: Tyler Stephenson
• 71st overall: Tanner Rainey
The No. 49 overall pick in the 2015 Draft, Santillan is from Seguin High School in Arlington, Texas. He is a Perfect Game first-team All-America selection and a member of the Texas All-Region first team.
Santillan is a power pitcher with scouting reports showing him throwing his fastball from 93-95 mph with the ability to reach 98 mph. He also has a strong 12-to-6 curveball that comes to hitters in the mid-80s.
However, Santillan is far from a finished product and will need some work. He also lacks a changeup, but the organization will develop him as a starter.
"Like a lot of high school pitchers, he needs some help with his delivery," Buckley said. "We're thinking he'll be able to figure it out. He's a really good athlete for a big guy, and he has two power pitches."
The Draft continues on Tuesday. The MLB.com preview show begins at 12:30 p.m. ET, with exclusive coverage of Rounds 3-10 beginning at 1 p.m. ET.
Santillan is committed to play college baseball for Texas Tech should he not turn professional. He is also represented by agent Scott Boras, but Buckley did not expect to have issues signing the pitcher.
"Or last two Drafts we got Mike Lorenzen [38th overall in 2013] and Taylor Sparks [second round, 2014]. They both have Scott Boras," Buckley said. "Hopefully we'll be able to get something done there. Usually when you pick them up there, you've done a lot of work, hopefully."
A couple of hours earlier on Monday evening, the Reds used their first-round selection (No. 11 overall) on catcher Tyler Stephenson from Kennesaw Mountain High School in Georgia. With the competitive balance round B pick, No. 71 overall, Cincinnati took right-handed pitcher Tanner Rainey from the University of West Alabama.
Mark Sheldon is a reporter for MLB.com. Read his blog, Mark My Word, follow him on Twitter @m_sheldon and Facebook and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.