The 2025 season has been full of growing pains for the Nationals, and not just in the standings. Several players expected to be steady contributors instead turned into liabilities, making an already difficult year even more challenging. With a little more than a month left in the season, Mitchell Parker, Nathaniel Lowe, and Trevor Williams stand out as the biggest disappointments.
Mitchell Parker
The Nationals hoped Mitchell Parker would take a step forward in 2025 after showing promise as a rookie, but he went in the opposite direction. Parker owns a 6.01 ERA and 1.49 WHIP, giving up 90 earned runs (the most in the majors) across 134.2 innings. His struggles with command (87 strikeouts to 53 walks) and a dip in velocity have left him overmatched. Hitters are batting .276 against him.
Over his last 21 starts, he has posted a 7.48 ERA, transforming from a potential rotation piece into a weakness for the Nats. At 25 years old, Parker has a -1.3 bWAR and clearly has declined instead of building on last year. Savant reflects Parker’s fizzle-out, ranking him near the bottom of the league in nearly every advanced metric.
Nathaniel Lowe
The Nationals brought in Nathaniel Lowe to be a middle-of-the-order bat after his several productive years in Texas, including a Silver Slugger season in 2022. Unfortunately, his performance took a major downturn in 2025. Lowe hit just .216/.292/.373 with a .665 OPS, the worst numbers of his career, while striking out at his highest rate ever (26.5%). He floundered so much that Washington designated him for assignment in mid-August despite owing him more than $10 million this year.
Previously a solid, everyday contributor, Savant’s grading confirms that Lowe’s bat and glove both collapsed in D.C., as he sits below average in nearly every category. To make matters worse for the Nationals, since they released Lowe, he has already found success in Boston. This quick turnaround only makes his short stint in Washington more frustrating.
Trevor Williams
After posting a 2.03 ERA in 2024, the Nationals re-signed Trevor Williams to a two-year deal, anticipating a steady veteran in the rotation. Instead, he never came close to repeating his prior success. Williams went 3–10 with a 6.21 ERA and 1.54 WHIP across 17 starts before a torn UCL ended his season.
Opponents hammered his diminished fastball, hitting .344 against it compared to .202 last year. Meanwhile, his velocity dipped to around 88 mph, one of the slowest in the league. Savant grades him below average in nearly every category, illustrating that the Williams deal turned into a letdown in 2025.