Lyles, a supplemental first-round pick in 2008, departed after allowing four runs (three earned) in five innings. He struck out four, walked three and allowed seven hits in Lexington's 5-0 loss. Lyles' 155 strikeouts (10.4 per nine innings) rank fourth in the minor leagues, while he also has a 3.16 ERA and 38 walks (2.6 per nine) in 133 2/3 innings.
"He wasn't his usual self," Lexington pitching coach Travis Driskill said. "He just didn't seem to have that put-away pitch that he's been having for the better part of the year. His curveball was a little bit loopier than it had been-it wasn't as sharp. These guys were ready to hit his fastball and I think he was struggling with fastball command. He was in the zone, but if he was trying to go away, he would leave it over the middle of the plate when he had a chance to locate."
Lyles has worked with his fastball at 90-91 mph most of the season. Throwing from a high three-quarters arm slot with what scouts have said is a fluid, repeatable delivery, Lyles threw his fastball at 89-91 on Monday, reaching 92 on a handful of occasions.
Being an athletic 18-year-old with clean arm action and a 6-foot-4, 185-pound frame, Lyles' average fastball velocity could increase as he fills out. The pitch already has late life that makes it a challenge for some hitters to square up.
"When I started the season, I wasn't going inside and out (with my fastball)," Lyles said. "If I throw a fastball outside, they can put the bat on it, foul it off into the stands. So a couple weeks into the season I learned to go inside and that's why all my strikeout totals have been up. Since then, just working in and out has been really successful."
Some evaluators who have seen Lyles this season he has a tendency to leave the ball up, but his command has generally been good, especially for his age.
"Overall, he's been terrific," Driskill said. "He locates his fastball as well as anyone should at this level. He does have a real good breaking ball, he's finding a slider and, then again, he has a real good feel for a changeup. For a kid who's only 18, he's got four pitches right there that we're talking about. And we know two of them are outstanding, and the two breaking balls are good and should get better as he matures and becomes a more experienced pitcher."
Lyles threw a curveball that he added and subtracted from. He threw his curve at 75-76 mph at times, while throwing a harder curveball at 79 with tighter rotation and sharper break.
While Lyles said hitters seemed to see his curveball well out of his hand in this particular start, talent evaluators who saw Lyles earlier in the year have said the pitch has shown good spin and sharpness.
"There's a couple curveballs I use," Lyles said. "I use a show-me curveball early in the count when they're not looking curveball-and that's OK to have a big loopy curveball to show them-but others I like to bury in the dirt, and I had plenty of opportunities tonight.
"I got ahead of a lot of guys tonight, but I couldn't put them away. I didn't have an out pitch tonight. I tried to put them away by throwing a curveball in the dirt and I was leaving it a little up, something where they could put the barrel of the bat on it. They put it in play, so I give them credit for putting it in play and getting hits."
Lyles didn't use a slider in the first half of the season, but in recent weeks he has started to mix the 82-84 mph pitch into his repertoire. While he threw his slider more than his changeup, it projects as a fourth pitch to keep hitters off balance with a different look.
"He came out of high school with it, but we wanted to concentrate on just having one breaking ball to see if we could get that going," Driskill said. "He was able to get it going-obviously not tonight-but it's been a real good pitch for him and we just add in that slider to give him a different look."
Lyles showed promising flashes with his low-80s changeup-which he said has been his second-best pitch going back to last season-throwing it to both lefthanded and righthanded batters. With one out and no runners on base in the third inning, Lyles missed away with a changeup in a 2-2 count to DH Ryan Keedy. Lyles struck out Keedy swinging on the next pitch with another changeup-his best of the night-with good sink and fade.
"For a young guy, he has a lot of confidence in that pitch," Driskill said. "His willingness to throw it shows that he'll be able to throw it when he gets to a higher level, and he'll be able to take that to the major leagues and keep guys off his fastball.
"It's always been there. I had him last year in (Rookie-level) Greeneville and we had some special rules about how we were trying to use some pitches because we wanted some more changeup use. When we did that and we made him throw it, he found out it was real good. It's just unbelievable for an 18-year-old kid to come out of high school and have a changeup like that."
This story was not subject to the approval of the National Association of Professional Baseball Leagues or its clubs.