WASHINGTON, D.C. - Washington Nationals left-hander DJ Herz landed on the 15-day injured list on Tuesday morning, due to a sprained UCL in his pitching elbow. The 24-year-old pitcher, who struggled through spring training with a 6.52 ERA and diminished velocity, now faces a potential season-ending setback. Just last Friday, the Nationals optioned Herz to Triple-A Rochester as one of their final camp cuts, a move that hinted at challenges but didn’t yet reveal the full story of his elbow injury.

In 2024, Herz emerged as a standout for the Nationals. Acquired from the Cubs in a 2023 trade for Jeimer Candelario, he debuted in the majors on June 4 and stayed in the rotation for most of the season. Across 19 starts, he posted a 4-9 record with a 4.16 ERA, striking out 108 batters in 88 2/3 innings. His best outings—like a six-inning, one-hit performance with 13 strikeouts against the Marlins on June 15 and a 10-strikeout gem against the Mets on July 2—showcased his potential as a key piece of Washington’s future.

During Spring Training, Herz couldn’t find his rhythm. Competing for the No. 5 starter spot against Mitchell Parker and Shinnosuke Ogasawara, he faltered with a 1.966 WHIP and nine walks in just 9 2/3 innings. His fastball, which averaged 93.5 mph in 2024, topped out at 91 mph during a March 13 outing against the Rays. At the time, Herz brushed off concerns, blaming his struggles on a typical spring training slump rather than injury. “My velo’s always down in spring training, my command is all over the place,” he said then, suggesting he just needed time to grind through it.

The Nationals gave him a chance to rebound, skipping another Grapefruit League start in favor of a simulated game on March 18. There, he threw 85 pitches over five innings, hitting 92 mph and showing signs of progress. Manager Davey Martinez noted improvement, saying the strikes and changeup looked sharper. Yet, the UCL sprain diagnosis now explains why Herz’s arm never fully came around, turning what seemed like a minor setback into a major concern.

Martinez had framed the Triple-A demotion as a chance for Herz to build up strength, noting his limited 19-start workload in 2024. “Just go down there and start getting built up,” Martinez said Friday. “He’s going to get ready to help us.” That optimism is on hold as Herz shifts focus to recovery.

The severity of the UCL sprain remains unclear—whether it’s a short-term issue or something requiring surgery could define Herz’s 2025 season. For a pitcher who became a breakout star in 2024, this injury is a frustrating hurdle. While the road ahead is uncertain, Herz’s youth and talent suggest he can bounce back, keeping hope alive for his return to Washington’s mound.