After Dean Kremer’s best start of the year, the Orioles informed the rookie right-hander they were optioning him to the minor leagues, using a pair of days off this week to shrink their rotation to four and carry an extra bullpen arm in the meantime.

With days off Monday and Thursday bookending their upcoming series in Miami, the Orioles won’t need a fifth starter until the following week’s home series against the New York Yankees, which lines up with the 10 days Kremer must spend at the alternate site in Bowie, their pseudo-Triple-A camp until that season begins next month.

“We’re going with four starters here with this unique stretch where we have two off-days in a week,” manager Brandon Hyde said. “Hopefully, it’s just a short amount of time [until] we can get Dean back in the rotation. That’s how we explained it to him. He was a pro, and he took it well and knows that we think really highly of him. He’s going to make a lot of starts for us the rest of the year.”

Kremer is one of several prospects who will get their shot in Baltimore throughout this season as more products of the club’s rebuilding efforts reach the majors. About a 10th of the way through the season, here’s a check-in on how those who have already arrived have performed.

Dean Kremer: Kremer made four starts at the end of the 2020 season, with a dud against the Boston Red Sox coming after three outings in which he allowed no more than a run in at least five innings. But his first two starts of 2021 looked more like that final outing. He failed to get an out after the third inning, allowing seven earned runs across six frames.

Although he was optioned afterward, his start Saturday against the Texas Rangers showed a path forward for him to be successful, as his fastball and curveball accounted for 90% of his pitches as he allowed one run in 4 2/3 innings. His curveball usage in particular was more in line with how he thrived last year.

Ryan Mountcastle: Projected as a fixture in the middle of Baltimore’s order, Mountcastle’s early struggles prompted Hyde to move him down to sixth. His continued adjustments to left field add to a disappointing start.

But there’s a lot of baseball left, and Mountcastle’s batting line of 180/.203/.295 is sure to shift toward the .333/.386/.492 effort he put up in 2020. Saturday, he barreled a ball the other way, nearly hammering a three-run home run but settling for a deep sacrifice fly. On Sunday, he had another flyball get caught on the warning track, this time in left, and a diving play by left fielder Willie Calhoun denied him of what would’ve been a go-ahead extra-base hit in the 10th inning. Once those hits start falling — or going over

the fence — Mountcastle’s numbers will align more with what the Orioles expect from him.

Bruce Zimmermann: Entering spring training as a bulk-inning candidate on a team trying to carry as many as possible, the Ellicott City native pitched his way into the Orioles’ rotation. And besides Opening Day starter John Means, Zimmermann has been the most productive member of it.

His first two outings met the baseline for a quality start — three earned runs in six innings — then he held the Seattle Mariners to two in five without his best stuff.

Ryan McKenna: Austin Hays’ hamstring injury made McKenna an early debutant for the 2021 Orioles, and Hays’ expected return Tuesday likely will send McKenna to the alternate site. But while there last year, he impressed the Orioles and continued to do so in spring training.

His major league performance thus far fits the profile he carries as a speedy, defensively skilled outfielder. He’s often come in late as a defensive replacement or pinch-runner, and his first career hit was a triple. The Orioles’ deepest area is the outfield, but McKenna has shown there can be a role for him in it.

Ramón Urías: Urías was typically lost when discussing Orioles who made their debuts in 2020. He joined the Orioles that spring as a waiver claim, but he’s worked his way into some prominence, with the team keeping him on the active roster over Yolmer Sánchez and Pat Valaika. He’s shown a knack for hitting the other way and up the middle, an asset Hyde always appreciates.

Tyler Wells: One of the Orioles’ two Rule 5 draft selections, Wells reached Double-A and made six appearances there in 2018, then missed the next two seasons between Tommy John surgery recovery and the pandemic. He’s handled the jump to the majors well thus far, allowing six baserunners in 5 2/3 innings, though two have been home runs.

Mac Sceroler: Sceroler, Baltimore’s other Rule 5 pick, is on the injured list with right shoulder tendinitis. His first two outings showed both his promise and the difficulty in moving from High-A to the major leagues. He worked 2 2/3 hitless innings against the Yankees in his debut, flashing an impressive split-change as he worked out of a bases-loaded jam.

But his second outing saw him give up five hits, including two homers, plus a walk and hit batter in one inning. Such performances are to be expected from players making the leap he and Wells are.

What’s to come?

The Orioles had an early visit to Miami scheduled last season, but a COVID-19 outbreak on the Marlins’ roster meant they went to Florida, never played a game and flew back to Baltimore. Instead, the teams later played four games at Camden Yards with the Orioles being the road team at their home stadium for two of them. Sandwiched between those days off Monday and Thursday, the Orioles will play a two-game series against the Marlins in their first trip to Miami since 2015. Afterward, they’ll try to improve on their 1-6 record at Oriole Park in a homestand that begins with a three-game series with the Oakland Athletics.

What was good?

In 2019, Means built his All-Star first half around pitching effectively in five-inning outings. Nine of his 14 starts before the All-Star Game lasted five innings or fewer. Even two years later, such starts are worthy of praise for an Orioles rotation striving to provide whatever number of innings it can.

In Baltimore’s latest turn through its rotation — from Matt Harvey’s start to open Thursday’s doubleheader with the Mariners to Means’ seven scoreless innings Sunday — all starters worked at least 4 2/3 innings and never allowed more than two runs. Means was the only one to pitch past the fifth innings, but the rotation collectively allowed seven earned runs in 26 1/3 innings, a 2.39 ERA, while striking out 28.

Within that stretch, the bullpen had a scoreless streak that last 13 1/3 innings, with pitching being a surprising strength of late.

“We’re such a young team,” Means said. “I think that when everybody’s doing well, you start to create that energy and start to build off that. I think some guys are really finding out who they are.”

What wasn’t?

Despite hitting his first double of the year in Sunday’s first inning, it was a rough week for Anthony Santander.

He was hitless after that, finishing the week 3-for-23 with seven strikeouts to one walk. In Sunday’s ninth inning, he got ahead 3-1 against Rangers closer Ian Kennedy, only to swing through two mid-90s fastballs and strikeout.

Over the past two seasons, Santander played in 130 games, slugging .505 and hitting 31 home runs. Hyde suggested that those successes are causing Santander’s current troubles.

“I think the league knows now that Santander is a run producer, a really good player, and honestly, they’re pitching him tough,” Hyde said. “You’ve seen a lot of balls in the corner, they’re crowding him, they’re elevating on him, a lot of balls in. And that’s why you see him kind of getting early, kind of cheating a little bit.”

Hyde referenced the first half of Thursday’s doubleheader, when Mariners left-hander Marco Gonzalez pounded him inside with sliders and cutters. Santander struck out three times in that game, part of 16 straight hitless at-bats before Sunday’s double.

“He’s a little frustrated, but he’s working extremely hard to kind of get back to what he does best,” Hyde said. “When you fall into a little bit of a rut, you start to think about what they’re doing to you instead of having your plan and your approach and sticking with it, and I just think he’s kind of gone away from that a little bit, and I think you could see him get hot real quick.”

On the farm

After the Washington Nationals’ coronavirus issues prevented their alternate site group from scrimmaging the Orioles’, the two clubs met up for a pair of contests this week.

In Tuesday’s game in Bowie, Yusniel Diaz, the centerpiece of the July 2018 trade that sent Manny Machado to the Los Angeles Dodgers, homered, but he didn’t play Friday in Fredericksburg because he was a member of the Orioles’ taxi squad for this road trip.

Left-hander Keegan Akin, who pitched himself out of Baltimore’s rotation in spring training, threw well in the Friday game.

“He’s working hard, he’s improving and throwing a lot of strikes,” Hyde said. “Hopefully, those guys are staying ready and waiting for the call.”