Yainer Diaz arrived on the scene in Houston like a shooting star. Acquired from Cleveland in the Myles Straw trade, his debut in 2023 seemed like the Astros had stumbled onto the second coming of Johnny Bench.
He’s gotten steadily worse every year. It’s as though he joined the Astros when he was 34 years old, not 24.
Will he continue to decline, or is there hope for Yainer Diaz?
First, let’s look at the back of his baseball card.
Here are the slash lines:
2023: .282/.308/.538. 23 home runs in 377 PAs,
and a 127 wRC+.
2024: .299/.325/.441. 16 home runs in 619 PAs, and a 116 wRC+.
2025: .256/.284./.417. 20 home runs in 567 PAs, and a 92 wRC+.
In short, Diaz has gone from an emerging superstar to a below-average hitter. What’s gone wrong?
The standard answer is plate discipline. Yes, it’s horrible. Among qualified batters, he has the absolute worst outside-the-swing percentage in the major leagues: 47.7% according to Fangraph Leaderboards. But this is partially offset by a well-above-average O-contact% of 66.8%, which kept his K% down to a relatively low 16.8% and his overall Contact% at a slightly above average 78.2%
But the wild ways with the bat do not explain Diaz’s decline. His rookie year was just as bad: 46.4% O-Swing percentage and a 62.2% O-Contact%. That and his overall Contact% of 74.9% were worse in his rookie season than in 2025. His swinging strike% has declined from 14.7 in 2023 to 13.0 in 2025, well better than league average.
Let’s get a little more granular.
Statcast measurements show greater consistency in Diaz’s hitting profile year-to-year, especially the last two years, than the baseball card does. His EV from rookie year to present: 90.3, 90.2, 90.0. Barrel%: 12.2, 7.6, 9.6. Hard hit%: 43.9, 47.5, 42.2.
Overall, his EV has remained generally stable; his Barrel% was actually better in 2025 than in 2024, although his Hard Hit% was its lowest in 2025. At 42.2, it is just below average among qualified hitters, but not much below that of Diaz’s stellar rookie year.
None of these numbers would predict a season 8% below league average hitting (wRC+ 92) that we saw in 2025. And, in fact, Diaz underperformed Statcast’s expected statistics.
BA: .256. xBA .279
SLG: .417. xSLG .488
WOBA: .300. xwOBA .340
That .340 xwOBA is better than Diaz’s 2024 wOBA and xwOBA. His .277 BABIP was by far the lowest of his career. ZIPs projects a 2026 .313 wOBA, about halfway between his 2024 and 2025 wOBAs.
One problem that stands out in 2025 is increased difficulty with breaking balls, especially cutters and sliders. Against cutters, Diaz went from 3.4 runs above average in 2024 to -2.2. Against sliders, the dip went from 6.2 runs above average to -4.5. I believe this is a problem team-wide, one on which the new batting coaches will hopefully focus./’
So, going into his fourth season at 27 years old, it doesn’t seem reasonable to expect Diaz to fulfill the high hopes we once had for an emerging All-Star-quality catcher. However, it is reasonable to believe regression will bring him back to at least his 2024 level, and, who knows, with new hitting coaches, he may recover some of the swag that made him so exciting in his rookie year.
