What’s causing Trevor Rogers’ slow start?

If one thing propels the Miami Marlins to a playoff berth, you’d figure it’d be the starting rotation. Recently extended Sandy Alcantara, despite some early struggles, has pitched to a 2.90 ERA over his first five starts. Pablo López is coming off an NL Pitcher of the Month award, allowing only one run during the entire month of April. Jesús Luzardo seems to have done a complete 180 in his first full season pitching in Miami. When right, even Elieser Hernandez is a serviceable big league pitcher.

On a per-inning basis, Trevor Rogers was better than any of them in 2021 en route to a NL Rookie of the Year runner-up finish. Less than one year removed from an NL All-Star nod, however, Rogers has severely regressed.

In 22 innings over his first five starts, the 24-year-old Rogers has pitched to a 1-4 record with a 6.14 ERA. By virtually every measure, he’s been a below-average rotation option for a Marlins team that’s determined to contend now.

How heavily should we weigh his sluggish opening month? Let’s look at how and why Rogers has performed so poorly out of the gate.

It appears the league has adjusted to the characteristics of Rogers’ pitches and his preferred sequencing, because opposing hitters are not chasing out of the strike zone as much as they used to. He finished in the 68th percentile in chase rate in 2021—that has plummeted to the 25th percentile in 2022. Consequently, he hasn’t been able to operate in favorable counts. Rogers got ahead 0-2 in 30.4% of plate appearances last season compared to 20.6% currently (the MLB average is 26.1%).

Photo by Eric Espada/Getty Images

Regardless of the situation, Rogers’ stuff is not working as intended. That is reflected in his lack of swing-and-miss. Per Baseball Savant, the Whiff% is down on each of his weapons—from 26.8% to 25.5% on four-seam fastballs, from 33.7% to 21.1% on changeups and 40.8% to 35.7% on sliders. Batters are “staying alive” long enough to capitalize on his mistakes.

The left-hander is allowing more hits, the same number as his innings pitched (9.0 H/9). During his breakout 2021, Rogers posted a H/9 of 7.2. He’s putting even more traffic on the bases via walks (4.5 BB/9). Outside of his most recent outing against the Diamondbacks, the former first-round draft pick is keeping balls in the yard, but he’s leaving himself little margin for error by permitting baserunners so frequently.

Rogers struck out 18.4-percent of hitters in his four April starts, a stark contrast from his 34.9-percent mark last April. He has yet to register more than 4 strikeouts in any appearance. That’s leading to extra balls in play. His .303 batting average on balls in play is similar to his 2021 mark (.307 BABIP).

How much of this slow start can be attributed to Rogers getting unlucky? Can he still salvage his season?

At the outset, we noted Rogers' ugly 6.14 ERA, but his 4.14 FIP indicates that he’s done a decent job of controlling what he can control. He is near the top of the list of starters with the biggest gaps between their ERA and FIP, a leaderboard that includes reputable arms like Kevin Gausman, Brandon Woodruff and Freddy Peralta. Same story with his xERA of 4.07.

After struggling somewhat with his slider in 2021—allowing a .452 xSLG—Rogers has made tangible changes, like throwing it 2.2 miles per hour slower on average to get a larger separation in velocity between it and his other pitches. So far, hitters have managed a .231 BA and .385 SLG against the breaking ball, but based on their lousy quality of contact, Baseball Savant foresees much better outcomes (.155 xBA and .168 xSLG).

The numbers may not tell the whole story, either. Consider the potential ripple effects of the lockout and abbreviated Spring Training on somebody like Rogers, determined to evade the dreaded “sophomore slump” but not having access to the Marlins’ coaches and analysts for most of the 2021-22 offseason.

“It’s hard to say that anything is a trend yet,” said manager Don Mattingly in response to the slow start by hitters, though one could apply the same logic to the other side of the ball.