Nationals infielder Carter Kieboom will miss the entire 2022 season, as he’ll undergo Tommy John surgery next week, manager Dave Martinez told reporters (including Jesse Dougherty of the Washington Post). The 24-year-old has been on the 60-day injured list since Spring Training because of a UCL sprain in his throwing elbow.
It’ll be a lost critical development year for Kieboom. A former first-round pick, the righty-hitting infielder later developed into one of the sport’s top prospects. He reached the big leagues late in 2019, his age-21 season. The following winter, Baseball America ranked the Georgia native as the most promising player in the Washington farm system and named him the #15 prospect league-wide. The hope was that he’d cement himself as the third baseman of the future after Anthony Rendon departed in free agency, but he’s not yet staked a claim to that job.
Kieboom didn’t hit for any power in 33 games in 2020, finishing the shortened season with a modest .202/.344/.212 slash line. His 13.9% walk rate was strong and reinforced a patient plate approach, but the lack of results on batted balls was jarring. That more or less continued over a larger body of work last year, as he posted a .207/.301/.318 line with six home runs through 249 trips to the dish. Kieboom again drew a fair share of free passes, but he also saw his swinging strike rate jump and posted well below-average exit velocities.
The Nationals’ summer sell-off and retooling year afforded a perfect opportunity to give Kieboom everyday run at the hot corner this season. Washington presumably won’t embrace a multi-year stepback with Juan Soto only controllable through 2024, but the Nats were clearly not positioned to compete this year. Giving 600 plate appearances to a talented but unproven player like Kieboom makes sense for a team in their position, and he’d have probably been the primary third baseman if healthy.
The injury will deprive him of that chance, and it remains to be seen if the Nationals can afford to be so patient in 2023. They’ll presumably be more aggressive in trying to compete next season, and bringing in a more proven option at the hot corner seems plausible. Kieboom, who will collect a full year of MLB pay and service time while recovering, is controllable through 2026 and won’t be arbitral-eligible until the end of next season. The Nationals are hopeful he can be ready for Spring Training.