Down the stretch last September, Orioles right-handed reliever Miguel Castro was on a two-month roll, seemingly in the midst of a low-key breakout. Then, a six-run blowup happened in his penultimate appearance of the year against the Blue Jays, ballooning Castro’s ERA back up around MLB average.

Such is the life sometimes of a young reliever searching for consistency, where progress can be erased by one big swing and the path to sustained success is often non-linear.

Now, one-fifth of the way through this 60-game regular season, the threat of one stat line-destroying blowup looms even larger every night. But the breakout that people have been waiting for since Castro debuted as a 20-year old with the Blue Jays appears to be here. Now 25, Castro has been one of baseball’s best relievers so far in 2020, starring in a multi-inning role in the Orioles’ improved bullpen.

“He’s really throwing the ball well, attacking guys, throwing a lot of strikes,” said manager Brandon Hyde, who has used Castro more than any of his other bullpen arms so far. “It’s all about strikes with Miggy, because his stuff is so good.”

Always Castro’s calling card, that stuff is better than it’s ever been. His sinker is averaging 98 mph, up 3 mph from two years ago and ranking as the second-hardest sinker in MLB. His changeup is averaging 92.3 mph and getting above-average break both vertically and horizontally, per Statcast. His slider has turned into a sweeping swing-and-miss pitch, which opponents are 0-for-6 against with five strikeouts.

(Also worth mentioning: Castro’s sinker and changeup are getting almost identical horizontal movement, per Statcast, mirroring each other in a way that suggests tunneling.)

Then, there is the command, which is largely improved. Castro entered 2020 with a 12-percent career walk rate, but he’s struck out eight against only one walk over 6 1/3 innings so far. He carried a 0.00 ERA into Thursday’s series finale against Miami after whiffing four across two scoreless innings in the Orioles’ loss in Game 2 of Wednesday’s doubleheader.

“Heading into the offseason, there were some ideas with the pitching coaches, and with all the downtime between March and now, I was able to put them in play and work closely with what they were telling me,” Castro said via an interpreter. “Right now, my mechanics feel very comfortable. I feel like I’ve got them there.”

That’s always been the crux with the 6-foot-7 Castro, who the Blue Jays traded to the Rockies as part of the Troy Tulowitzki deal in 2015. He then arrived in Baltimore via trade in April 2017. Since then, the O’s have worked tirelessly to help Castro repeat his delivery better and miss more bats, while getting good-but-not-great results (110 ERA+ over three seasons). This year, he’s doing both, and dominating.

“There is no doubt I feel more confident in throwing my secondary pitches and mix of pitches,” Castro said. “In the end, it’s about work. I’ve worked this whole time to get a feel for what I’m doing.”

From the trainer's room
The Orioles lined up against the Marlins on Thursday without third baseman Rio Ruiz for the fifth straight game, as Ruiz remains sidelined with a sore right shoulder. Hyde said he was hopeful Ruiz, who has not played since Saturday, could return to the starting lineup over the weekend.

Ruiz, 26, had been one of the bright spots for the Orioles early, hitting .318 with three homers and an 1.112 OPS over his first six games. He hit .232 with 12 homers and a .682 OPS in 127 games in 2019, his first full season in the Majors.

Pat Valaika started at third base, while Renato Núñez, who had been getting regular reps there, shifted to designated hitter. Núñez had an error in both of his starts at the hot corner.

Back in full
The prognosis is better for José Iglesias, who returned to shortstop Thursday after being limited to DH and pinch-hitting duties for a week while dealing with a sore left quad. He entered Thursday hitting .458 with six doubles and an 1.188 OPS as Baltimore’s regular No. 3 hitter.

Schedule update
The Orioles-Yankees game originally scheduled for Aug. 5 will be made up as part of a doubleheader on Sept. 4, MLB announced Thursday, which will begin at 5:05 p.m. ET and open a four-game series at Camden Yards.

The Orioles also had the time of their Aug. 19 game against the Blue Jays changed from 7:35 p.m. ET to 1:05 p.m. ET.