BALTIMORE -- Just as the Orioles’ rotation was nearing full strength, the team’s pitching staff was dealt an unexpected big blow Wednesday afternoon.

Baltimore placed right-hander Grayson Rodriguez on the 15-day injured list with right shoulder inflammation. It was a surprising move after the 24-year-old tossed 5 2/3 scoreless innings in the O’s series-opening win over the Yankees at Camden Yards on Monday.

In a corresponding transaction, the Orioles reinstated left-hander John Means (left forearm strain) from the 15-day IL. It is not yet known when the 31-year-old Means will make his season debut, but he is rejoining the rotation and should get a starting nod during the team’s upcoming weekend series at Cincinnati.

Rodriguez joined fellow righties Kyle Bradish (right UCL sprain) and Tyler Wells (right elbow inflammation) on the injured list. However, Bradish is slated to be activated at some point this week and could start Baltimore’s series finale vs. New York on Thursday afternoon.

On Tuesday morning, Rodriguez woke up and felt soreness in his right shoulder, per manager Brandon Hyde, who is “hopeful” it won’t be a long-term issue for the former top prospect. Rodriguez was still undergoing testing as of Wednesday afternoon.

“I’m staying optimistic. We’re definitely doing this to be precautionary,” Hyde said. “Just wanted to give him at least a couple weeks off to let everything kind of calm down. He’s a big part of our rotation. We need him this year. So we’re just giving him some time off.”

Through the first six starts of his sophomore big league campaign, Rodriguez had a 3.71 ERA and a team-high 37 strikeouts over 34 innings. Rodriguez picked up where he left off in 2023, when he had a 2.58 ERA in 13 second-half starts.

Rodriguez went at least 5 2/3 innings and allowed two or fewer runs in five of his first six outings this year, the only exception being a tough start vs. the Angels on April 23 (seven runs allowed in 4 1/3 innings).

With Means active and Bradish soon to be, as well, it was widely expected that Baltimore would bump left-hander Cole Irvin and righty Albert Suárez from the rotation. Both are out of Minor League options, so it seemed likely they could be ticketed for the bullpen.

However, one of them should continue to serve as a starter now that Rodriguez is out. It’s more likely to be Irvin, who has a 3.49 ERA through five starts and is currently riding a career-long scoreless streak of 14 1/3 innings.

Means had to be reinstated by Wednesday because his 30-day Minor League rehab assignment had ended. He recorded an 8.68 ERA in six starts for Triple-A Norfolk, but he finished on a strong note, tossing seven scoreless innings with one hit allowed, one walk and eight strikeouts in a 95-pitch outing vs. Gwinnett on Sunday.

“I felt really good, felt healthy, which is the main thing. And then last outing really clicked, so I’m ready to go,” Means said. “Just try to carry that over.”

Added Hyde: “That last outing, that was a real positive. ... For me, that was the real tell that he’s ready to get back in the big leagues.

Since the start of the 2022 season, Means has made only six starts for Baltimore. He had a pair of starts in April of ‘22, then underwent Tommy John surgery. He returned last September and pitched to a 2.66 ERA in four starts to close out the ‘23 regular season. However, a flare-up in his left elbow caused him to miss the AL Division Series.

Means was an All-Star in 2019. He threw the sixth no-hitter in O’s history on May 5, 2021, at Seattle. He also owns a 3.74 ERA in 74 career MLB outings (69 starts), so he’s capable of providing a major boost.

The Orioles (19-10) entered May in first place in the American League East and tied with the Guardians for the best record in the AL, and they have yet to see their five best starters (ace Corbin Burnes, Bradish, Rodriguez, Means and Dean Kremer) all healthy at the same time. Their 3.60 rotation ERA ranks seventh in MLB and sixth in the AL.

While Baltimore believes its starting staff could eventually have all of its pieces later in the first half, more injuries could occur, which is why it’s important to have depth.

“Right now, with pitching in general, you’re just hopeful,” Hyde said. “That’s why it’s tough to be too optimistic or be too pessimistic. You just don’t know what’s going to happen.”