Jon Meoli: Luis De León’s fastball focus once again saved his season. This time, it brought him to the big leagues.

Luis De León had been in this position before.

Last summer, he’d felt stuck in High-A before a meeting with a group of pitching coaches who provided the blueprint for how to use his fastball better. He turned his season around.

This year, carrying sky-high expectations based on how well he threw the ball from that point on, he was similarly scuffling. Both he and the Orioles expected he’d help in the big leagues this year, and that wasn’t the track he was on.

Again, it came back to the fastball and how the 23-year-old lefty attacked all the righties he’d see as he moved closer to the big leagues.

“What’s his plan? What does he have to turn back to when he needs to be really good when something goes south?” Double-A Chesapeake pitching coach Jeremy Hileman said.

The answer to that — using his sinker inside to righties — set De León on the course for Coors Field on Tuesday, where he made a major league debut that a few months ago would have felt unlikely. And for a pitcher who both evokes comparisons to Phillies ace Cristopher Sánchez and loves to study him, the solution is one that puts De León on a promising path.

Last summer at High-A Aberdeen, De León was underperforming after a late start to his season due to an elbow issue when, essentially, an all-hands meeting with the Orioles’ pitching brass laid out the path forward. He was in the zone plenty with his fastballs but wasn’t locating them in ideal spots to righties, and that was severely pulling down his results. Once he locked in on locating his four-seamer and two-seamer optimally, he took off. De León struck out 64 in 45 innings with a 1.80 ERA in his last nine starts between there and Double-A Chesapeake, then starred in the Arizona Fall League.

That made his start to the 2026 season in Double-A all the more frustrating. De León made a good impression in big league camp but struggled with his tempo and command in the first month or so with Chesapeake.

Hileman said he’s at his best when he’s in a rhythm, and that was the first step. His identity against lefties — “bowling balls that are at you, and sliders that are going to collect whiffs,” according to Hileman — was established. But the Orioles again needed to focus his arsenal against righties, and the solution was to de-emphasize his four-seamer and have De León establish his sinker as his way to get ahead of and get the same weak contact on the ground against righties as he does lefties.

“The sinker is really, really good,” Hileman said, “and we don’t want to stray too far from it because it’s such a good option to get ahead in counts, get early weak contact, which obviously, for him to be a good starting pitcher, you want them to pitch deep in games, and getting weak contact early in counts is going to really help your cause.”

Hileman was De Leon’s pitching coach in Aberdeen for the adjustment that jump-started his breakout as well, and saw there were obvious parallels.

“Once he started doing it with some consistency, it really went his way,” he said. “I think it was no different than last year in that sense. If anything, him having just an OK beginning of last year and then taking off and doing what he did, hopefully gave him a little added confidence that, like, ‘Hey, we’ve seen this before. We’re going to be just fine.’”

This time around, Hileman was able to demonstrate how the approach would work. De León loves to watch Sánchez, the Phillies’ hard-throwing lefty who was second in the NL Cy Young voting last year and has been an All-Star twice.

When Sánchez was coming up in the Phillies system, he too had a phase where he dialed back his pitch mix and emphasized the two-seamer to help him solve righties.

Hileman said: “Showing him, even just execution and location plots on the sinker and slider and changeup and how [Sánchez] uses them and just how much that can open things up for him if he gets to or works towards that level of execution in similar fashion, that was one of the first pieces I pulled for him when we were really hammering down and pushing to be able to execute it into right-hander hitters, just really show him the evidence that there’s a chance that that could really, really work if you really master that skill.”

Using the sinker to righties, particularly in the zone, also improved his secondary pitches — the slider, changeup and his emerging splitter. For a right-handed hitter to be on time for a sinker on his hands, he’ll have to commit early, which makes De León’s off-speed pitches on the outer half play better. And even when De León missed his spot arm-side with the sinker, it was still in the zone, allowing him to keep counts competitive and still getting the weak contact that’s been a hallmark through his career.

His last seven starts at Chesapeake — with a 2.06 ERA, 1.00 WHIP and 42 strikeouts in 35 innings — meant he was more than ready for Triple-A. When he got there, he made a few starts before the Orioles shifted him to the bullpen to prepare for the September role he was given in the majors Tuesday.

“I think he has a slow heartbeat and doesn’t hit the panic button when things aren’t going well,” Chesapeake manager Roberto Mercado said. “You would never tell a difference if he’s throwing a no-hitter through eight or if he got hit pretty hard in the first inning. You couldn’t even tell when he comes off the mound. I think having that mindset is going to help him big-time.”