BRADENTON, Fla. -- The Pirates optioned top prospect Mitch Keller to Triple-A Indianapolis on Saturday as part of their first round of Spring Training roster cuts.

Keller, the No. 19 overall prospect according to MLB Pipeline, allowed 10 runs on 10 hits and three walks while recording just one strikeout in four innings of Grapefruit League play. He will begin the season in Triple-A, but the Pirates hope he will bolster their rotation at some point this season.

“Obviously no one likes getting kicked in the teeth like that,” Keller said before leaving the Pirates’ clubhouse at LECOM Park. “So I’m ready to go, ready to get back after it and really hone in on some stuff.”

In addition to Keller, Pittsburgh optioned right-handers JT Brubaker and Luis Escobar to Triple-A. The Pirates also reassigned right-handers Dario Agrazal and Eduardo Vera, left-handers Elvis Escobar and Blake Weiman and catcher Jason Delay to Minor League camp.

There are now 54 active players in Pirates camp, including 18 non-roster players.

None of the Pirates’ moves on Saturday came as a surprise. Keller, 22, needs more time in Triple-A after an up-and-down debut in Indianapolis last season. He allowed 13 runs in his first two Triple-A starts, then -- after an impressive appearance in the All-Star Futures Game -- posted a 3.09 ERA with 44 strikeouts in 43 2/3 innings over his final eight starts.

“He made a quick adjustment and, had we kept him in camp, he probably would have made a quick adjustment and been ready,” general manager Neal Huntington said. “He’s not the first and not the last guy to have some struggles in Spring Training. But what’s really encouraging is his attitude about it going out. It’s not what he wanted. It’s not what he expected. But he’s ready to tackle it head-on and go attack Triple-A and earn his way to the big leagues.”

Keller was hit hard this spring. He allowed three home runs in four innings. He didn’t think his struggles were comparable to his early slump in Triple-A, noting that he was “still trying to feel things out, feel pitches out, get them where I need them to be” in his first big league camp. His fastball velocity was still coming around, and he was working on developing his changeup -- his third-best pitch.

“We know and he knows that we never really saw the real Mitch Keller this spring,” Huntington said. “He’s going to go work on some things and be Mitch Keller again.”

Keller was pleased with his second inning on Friday, a scoreless frame in which he struck out Richard Urena with a nasty curveball, and felt he gained a lot from working with the Pirates’ pitchers and coaches.

“Obviously not the way I wanted them to go, but it was a really good learning experience. Excited to go back down, get some work in, build my innings up and get ready for the season,” Keller said. “Try to get my body right and my pitches and everything right where I need them to be so I can get that call-up in midseason or whenever it is.”

Keller will start the season in Indianapolis’ rotation alongside Brubaker, the Pirates’ Minor League Pitcher of the Year in 2018. Brubaker, Pittsburgh’s No. 21-ranked prospect, put up a 3.10 ERA in 22 starts for Indianapolis last season. He allowed only one run on five hits while striking out five over six innings this spring.

“JT’s been a guy for about four years now that we’ve liked much more than the external noise on him,” Huntington said. “It’s a power fastball. It’s a really good slider. It’s a good, smart man that, like Mitch, is learning how to use his stuff. … We like JT a lot, and he did nothing but reinforce our belief in him this spring.”