In 109 games for Triple-A Fresno, Kieboom finished the season with a .303/.409/.493 slash line, and MLB Pipeline has selected Kieboom and left-hander Tim Cate as the Nationals' Hitting and Pitching Prospects of the Year, respectively, for 2019. Cate, the No. 6 prospect in the Nats’ system, earns the honors after posting a 3.07 ERA in 26 starts in his first full season as a professional.
Each team's Hitting and Pitching Prospects of the Year were chosen by the MLB Pipeline staff. To receive consideration, players must have spent at least half the year in the Minors and appeared on the team's Top 30 Prospects list. For a Nationals system that has graduated a ton of talent in recent seasons, Kieboom and Cate represent two of the bright spots in the organization.
Kieboom, who turned 22 this month, is still the most promising player in the Nationals’ system. He made his Major League debut in April after a slew of injuries in Washington, and after homering in two of his first three games, he looked as if he might stick. But Kieboom ultimately struggled to a .491 OPS, a 37.2 percent strikeout rate and four errors in the field in 11 games before he was sent back down.
Once he returned to Fresno, he did not miss a beat, continuing to torment opposing pitching staffs while also refining his plate discipline. His strikeout rate in the Minors this season was 20.2 percent.
“He did a great job of learning the strike zone and becoming more disciplined as a hitter,” Mark Scialabba, the Nationals' director of player development, said during a phone interview. “Staying in the strike zone, looking to do damage with pitches he can handle. He’s always looking to improve his plate coverage and just being able to hit the ball to all fields and really take his walks if they’re going to give them to him and be someone that can drive in runs if they’re on base.”
Instead of calling up Kieboom again in September, where his playing time would be limited, the Nationals sent him to their Spring Training complex in West Palm Beach, Fla., where he could continue receiving at-bats and work in the field. The Nats continue to insist that Kieboom is a primary shortstop, but they have also had him continue to take reps at second and third base.
“Kind of to prepare as much as possible for any sort of opportunity that could arise at the Major League level,” Scialabba said. “Could be at second, could be at third, could be at short, depending on our needs at that level. He did a nice job.”
The Nationals have built a foundation on pitching, and they reason to be optimistic after an encouraging first full season from Cate, their second-round pick from the 2018 Draft. Cate, who turns 22 this month, threw 143 2/3 innings between Class A Potomac and Class A Advanced Hagerstown with 139 strikeouts and 32 walks.
The jump in workload from college to the pros usually makes it difficult for a pitcher to maintain velocity and stamina throughout the year, but Cate impressed the Nats by the way he finished the entire season -- and with a curveball that should be a major weapon on the mound.
“Great year, very consistent. In that first year, we really try to lay the foundation,” Scialabba said. “But what separates him from a lot of the really young pitchers is he’s got a weapon in his breaking ball. His curveball that he relies on to finish hitters, but also can get it early in the count for a strike as well.
“Very happy with where he was to start the year and where he finished, and just the consistency of him.”