After some early-season struggles, Mitch Keller is developing a pitch that may just make him unhittable.
Relying on his changeup, the Pirates' third-ranked prospect struck out nine over seven innings in his second straight scoreless start as Class A Advanced Bradenton defeated Dunedin, 4-0, on Friday at LECOM Park.
"I was just getting ahead with the fastball and mixing in curveballs and changeups," Keller said. "My changeup is a big thing I'm working on this year. Just really throwing that for strikes helped a lot. I was getting a lot of swings and misses on it."
After fanning the first two batters he faced, the right-hander had a sense of what was brewing.
"You always get a feeling after the first batter of what kind of night it's going to be," Keller said. "After the first inning, I had a feeling that it was going to be a pretty good night."
Keller hit Danny Jansen with a pitch with two outs in the fourth but got Juan Kelly to line out to second baseman Alfredo Reyes to end the inning.
The 21-year-old Iowa native surrendered a single to center field by Lane Thomas leading off the fifth, but he was thrown out trying to steal second base. After striking out Connor Panas, Keller gave up another base hit to Matt Dean before fanning Kevin Vicuna to end the frame.
Keller retired the side in order in the sixth and seventh, ending each inning with a strikeout.
Video: Bradenton's Keller notches ninth K
"My stuff is always hittable. It's just about picking the time to throw it and keeping the hitters off-balance," the 2014 second-round pick said. "I think that's a huge thing that my catcher, Christian Kelley, and I had tonight. Just keeping them off-balance was the key to getting a lot of swings and misses tonight."
Keller threw 59 of 85 pitches for strikes. He needed 97 pitches to get through seven scoreless innings -- fanning nine -- in Sunday's 4-2 win over Charlotte.
"You always want to go back out there for as many [innings] as you can go," Keller said, "but they told me I was done and I was happy with how I did, so I can't really complain too much."
Keller's two solid starts have reduced his ERA by nearly two runs per game to 2.88, and he's looking for ways to improve the newest pitch in his repertoire.
"I'm just working on being able to throw it for strikes and using it as a putaway pitch," he said. "Just working on good counts to throw it in and relying on my off-speed for strikes earlier in the count."
Jake Brentz struck out three and walked two over two innings for his first save of the season.
Kelley supported his batterymate with three hits, including a homer, and three RBIs.