He fanned 94 batters, good for a 12.82 K/9 ratio, and was named the National Junior College Athletic Association Player of the Year on Thursday.
After playing shortstop almost all of his freshman year, Fillmyer decided to devote his full attention to the mound.
"It was relatively simple," he said Friday. "I got drafted throwing 7 1/3 innings. What's going to happen if I devote my life to this?"
The Draft concludes Saturday, with exclusive coverage of Rounds 11-40 beginning on MLB.com at 10 a.m. PT.
Fillmyer sits in the low to mid 90s with a fastball that can reach 97 mph, and he features a strong curveball with a 12-6 break.
Despite being relatively new to pitching, Fillmyer has done his best to soak up as much information as possible on the craft.
"I pick up a lot of stuff that the professionals do, I listen a lot, and when I'm not at the gym or at school, I'm learning stuff," he said. "I watch a lot of YouTube videos on mechanics.
"One of my favorite pitchers to watch is Pedro Martinez," he added. "I watch a lot of his mechanics and his velocity, and just his power from his legs. I try to replicate that myself. Obviously I'm nowhere close to the pitcher he is, but I definitely just try to pick up little things."
Aaron Leibowitz is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.