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VENTURA, CALIF. - The Uncommitted Spotlight Series continues after a jam-packed preseason of Prep Baseball California events, winter scrimmage high school baseball, and other opportunities to evaluate players. We will be recognizing some of the top remaining uncommitted players around the state. We will be looking at players from the 2026 and 2027 classes across the upcoming weeks/months as the spring high school season begins to ramp up. 

We invite you to get to know them through the eyes of our Prep Baseball California staff of scouts, both through our in-person looks at players and/or the data-backed numbers collected at our events with our partnered companies. TrackMan, Blast Motion, and VALD Performance provide comparable data to project and evaluate players. All of these systems come together to give a clear picture of what colleges will get when a player steps onto their campus.

Today, we put the spotlight on a strong 2027 player who is coming off a solid junior high school season and shone on the Prep Baseball California event platform during the preseason. We are looking at SoCal '26 OF/RHP Caleb Koster from Cajon High School in San Bernardino, Calif. A returning varsity starter at Cajon, Koster is coming off a sound sophomore season with the Cowboys program in 2025. In late January, Koster made his Prep Baseball California debut at the Inland Empire Preseason ID with a strong performance, backing up his sophomore season of in-game performance.

The 2025 spring season was a solid overall year for Koster on the position player side of his profile. Playing in 26 games for the Cowboys, the RH hitting OF took 88 plate appearances with 67 official at-bats. His year displayed a consistent ability to put the ball in play, collect hits, and get on base with a slash line of .299/.460/.358 during his playing time. Koster had 20 total hits for the Cowboys, with three of those going for extra bases (two doubles and one triple). His on-base ability helped him score 26 runs as a table setter with six RBIs. Showing a discerning eye with 11 walks compared to eight strikeouts, while flashing toughness with nine hit by pitches on the year. His 12 stolen bases on the year were good for second on the team, and he posted an 80%+ success rate on the year. 

With solid in-game performance numbers, Koster's appearance at the Inland Empire Preseason ID was an opportunity to see how the tools match up to the in-game performance. Measuring in at 6' 153 lbs. Koster is wiry, but athletically built with room to add strength to his present frame, and adds in sound athletic ability with a 6.98 60 and an impressive 1.59 10-yard split showing the twitch in his profile. His defensive workout was a testament to long-term ability to stick at one of the prominent defensive outfield spots, including the arm strength upside to handle RF throwing 87 MPH on the day from the OF.

Koster is soundly backed up by his swing metrics and batted ball data for a present quality profile with upside as he continues to mature. Starting with a higher hand set and barrel angled behind his head, Koster employs a simple, balanced load with a short toe tap stride to reach the launch position. He has a rhythmic operation with a more direct bat path geared toward contact and a scissor kick on the back side to keep his direction through the middle of the field. Consistently on time to the launch position allowed Koster to produce 68.6 MPH of bat speed and 22 MPH of hand speed, both of which are solid present metrics and at a consistent rate. With a sound feel for his timing/rhythm and a direct bat path, he showed off high hit tool metrics during batting practice, including a strong 75% fly ball-line drive (ball in the air) rate. Koster's approach plays to more solid than loud contact, but he gets there at a consistent rate with 85.9 MPH max EV, a 78.9 avg EV, and 289' max distance from a direct path, which suits his present skill set. 

While Koster didn't see innings on the mound as a sophomore at Cajon, he threw a strong bullpen session at the IE preseason ID that gives you reason to believe time on the mound is in the righthanders future. During the bullpen session, Koster flashed a clean, repeatable delivery with sound direction down the mound and quick present arm speed. The stuff coming out of the righthanders operation was solid across the board. Throwing a FB in the 83.4-85.2 MPH range while peaking at 86.1 MPH that can get spin rates north of 2000 RPMs while generating 6'4" of extension on the offering from a 4'6" release height. He spun an emerging breaking ball with north of 2100 RPMs of spin in the 67-70 MPH range that can be polished as he matures. The righthander flashed a sound present CHG at 73-75 MPH efficiently killing spin as low as the 1200 RPM range, producing arm side fade and vertical separation off his FB shape while maintaining a similar release height at 4'5" and 6'8" of extension on the pitch. Koster controlled his FB effectively, but can improve his feel for controlling both the offspeed offerings to reach his potential as a pitcher in the future.

Building on a solid sophomore season of stats for Koster will be key for his long-term profile while continuing to mature physically, but the foundation of what Koster presents as a collegiate potential player makes him a solid overall name to know in the 2027 class out of Southern California.

To see his full video and information on Koster, dive into his profile here.

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