Jason Adam's Injury Will Hurt Padres More Than His WAR Suggests

Few relievers present a statistical contradiction as striking as San Diego Padres fireman Jason Adam in 2026. His 2.51 ERA still points to a pitcher capable of handling high-leverage innings. His slider continues to generate whiffs at an elite rate. His changeup still has the movement that has kept hitters off balance for years. Yet one of the most widely used metrics for evaluating pitchers tells a completely different story: His fWAR is negative.

The contradiction raises an obvious question: how can a reliever pitch this well and still grade out below replacement level?

The answer isn't a new pitch or a dramatic change in his arsenal. Rather, it all starts with the fastball. It's the pitch that holds the rest of his profile together. Adam never needed elite velocity on his four-seamer to build his success. Its job is to force hitters to protect the top of the strike zone, making both the slider and changeup even more difficult to recognize.

Pitch location explains that role better than any statistic. Adam still attacks the upper part of the strike zone with his four-seam fastball. It still has enough carry to challenge hitters' natural swing plane and create the contrast that allows his slider and changeup to play up.

Viewed in isolation, the fastball's trend is concerning. Its whiff rate has declined every year, hitters are making more contact, and the pitch's run value has collapsed in 2026. If that were the whole story, it would be reasonable to conclude that Adam no longer has a fastball capable of supporting a dominant arsenal.

And yet, the rest of his repertoire tells a different story. His slider remains one of baseball's best put-away pitches. In 2026, it's produced a 19.0% swinging-strike rate, while hitters have chased it outside the strike zone more than 40% of the time. His changeup also retains virtually the same horizontal movement profile and velocity separation that have made it an ideal complement to his fastball for years.

In other words, the decline of Adam's four-seamer hasn't spread to the rest of his arsenal. So, if both secondary pitches are still working, why has his overall value dropped into negative WAR territory?

Because fWAR doesn't evaluate how pitches complement one another within an arsenal. Its calculation starts with the outcomes pitchers control most—primarily strikeouts, walks, and home runs—before converting that performance into wins above replacement. That methodology captures the outcome of a pitcher's performance, but it doesn't always account for how one pitch enhances another within the same repertoire.

That decline shows up clearly in xFIP, the metric that serves as the foundation of FanGraphs' pitcher fWAR.

It's no coincidence that Adam's xFIP is now the highest of his career since debuting with the Royals in 2018. His HR/FB rate has nearly doubled from the previous two seasons, and four of the five home runs he has allowed this year have come against a four-seam fastball that has lost some of its ability to dictate at-bats.

Adam's negative WAR doesn't mean he has stopped being a dominant reliever. It shows how much a diminished fastball can affect the metrics that underpin fWAR. His slider remains an elite pitch, and his changeup retains much of what made it so effective. The decline of the fastball—the foundation of his arsenal—is enough for the model to tell a far less favorable story. It's why, Adam, now out with a shoulder strain, will be dearly missed by the Padres.