When it comes to switching from catcher to pitcher, Percival speaks from authority. He did the same thing in his playing days, and he became a dominant reliever. The closer on the Angels' 2002 World Series championship team, Percival pitched from 1995-2009. His 358 career saves rank 11th on the all-time list.
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These days, Percival is the head coach at UC Riverside, and he sees plenty of potential in Lillie.
"From the first time I put him on the mound, it was just a natural," Percival told MLB.com on Tuesday. "It reminded me of me, because the first time I jumped on the mound, I was able to throw strikes. I was able to spin a breaking ball. Once I saw that, I said, 'We're just going to work mechanically.'"
Lillie bought in immediately.
"He allowed me to kind of mold what I wanted," Percival said.
Listed as 5-foot-11 and 210 pounds, Lillie is scratching the surface of his potential. Percival feels he profiles as a reliever, but with a four-pitch mix, he has the tools to start.
"You're going to find a very competitive guy," Percival said. "He's as competitive as anybody."
Lillie made 20 appearances (10 starts) and had a 4.69 ERA, and he struck out 80 and walked 20 in 71 innings.
"He's definitely a strike-thrower," Percival said. "He can throw all four pitches for strikes, counting the two-seamer as an extra pitch. It does have substantial movement in on the right-handers. When he starts to learn to get a little bit of depth on that, it's going to be a little more dominant."
Lillie was one of eight college players selected by the Marlins on Day 2 of the Draft. On Monday, the club selected left-hander Trevor Rogers from Carlsbad High School in New Mexico with the 13th overall pick.
Lillie's fastball velocity has improved in each of the past three years -- going from 89-91 mph as a freshman to 91-93 as a sophomore and 92-97 this year.
"He's taken a very active role in his growth," Percival said. "He's in my office all the time talking pitching. He's gotten much more intelligent. I allow him to call his own game. That was done on purpose, so he would start to understand when he makes mistakes. We'd talk about it, understand that he's a fastball pitcher. I think sometimes he got a little bit happy throwing that breaking ball, when he's really a dominant fastball pitcher."
The Draft concludes on Wednesday, with exclusive coverage of Rounds 11-40 beginning on MLB.com at 12 p.m. ET.