Matt Waldron Can't Replace Nick Pivetta, But He Can Save His Padres Career

With Nick Pivetta facing an extended absence with a flexor strain in his elbow, the San Diego Padres will need to deploy their starting pitching volume earlier than they might have anticipated. Each of Griffin Canning and Matt Waldron were already on rehab assignment, but it’s the latter that’ll get the first call in Pivetta’s stead. He’ll start on Friday against the Los Angeles Angels. 

It remains to be seen what the Padres will get out of Waldron. The runway may be short, though. 

Two years ago, Waldron looked like a viable candidate to fill out the back of the rotation. Armed with an effective knuckleball, he posted a 1.8 fWAR across nearly 150 innings in 2024. While the stuff didn’t play on the strikeout side (21.3 K%), he was effectively able to navigate hitters by minimizing baserunners (6.4 BB%) and avoiding hard contact (35.0 Hard-Hit%). He was unable to replicate those results in 2025, however. 

After an oblique strain set him back to start the year, Waldron made only one start at the top level for the Padres. He was unable to make it through five innings due to some heavy command struggles; he allowed six hits and six walks in that outing. The results weren’t much better in Triple-A. He pitched to a 6.67 ERA (4.99 FIP) and had a hard-hit rate that lingered around 40 percent. His 52.0 percent usage on the knuckleball represented easily his highest usage of that pitch, and while he was able to get decent results with it (24.1 Whiff%), none of his four-seam, sinker, or sweeper proved capable of providing sufficient results. 

His trio of rehab starts here in 2026 have yielded very different results, however. In 12 innings of work, Waldron has yet to allow a run. He has a slightly improved strikeout rate (30.8 percent) but has demonstrated top-tier command (2.6 percent walk rate). His groundball rate sits at an obscene 64.0 percent. What’s most interesting about this turnaround in performance, though, is that it appears to be wrought by a dramatic change in usage. 

Waldron has cut the knuckleball usage by more than half. Through those dozen innings, he’s only throwing it 25.6 percent of the time. That’s led to more of a three-pitch blend of the knuckle, the four-seamer (26.9 percent), and the sinker (23.7). The sweeper has come in roughly 17 percent of the time as a fourth offering, registering as his best pitch in the eyes of Stuff+ (100). He’s gotten chase regularly with the former three pitches and has been able to generate more frequent whiffs on the knuckle (27.3 percent), at least partially a byproduct of the more frequent incorporation of the other two. 

If that’s the version of Waldron the Padres get on Friday, then he can certainly help to stabilize the rotation in Pivetta’s absence. This is not a starting group in search of strikeouts; it’s about mitigating quality contact in the very way that Waldron has done thus far in El Paso. If the command is even close to as pinpoint as it’s been in Triple-A, his enhanced pitch mix should suit him (and the group) quite well.

In truth, Waldron needs that to be the case.

Even with Pivetta down for an extended period of time, the Padres are otherwise squared in their rotation at present. Each of Michael King and Randy Vásquez has been very good (the latter’s most recent start notwithstanding). Walker Buehler and Germán Márquez have produced varying results start-to-start but have more established big-league track records. With Griffin Canning also likely nearing the end of his own rehab and Joe Musgrove (presumably) returning eventually, there’s a certain onus on Matt Waldron to look good quickly. 

It’s not so much that he’s pitching for his job on Friday, but it’s not as if he has an extended runway either. There’s a needle in need of threading here, and Waldron will need that four-seam/sinker combination to work in conjunction with the knuckleball to drive his success or his out-of-options status could lead to some rather shaky ground in short order.