BALTIMORE -- Grayson Rodriguez, the top pitching prospect in baseball, has been diagnosed with a right lat muscle strain that will sideline him “probably a decent amount of time at a minimum,” Orioles executive vice president and general manager Mike Elias said Thursday afternoon -- a development that will delay Rodriguez's much-anticipated Major League debut.

The news came prior to the Orioles' 7-6 loss to the Mariners on Wednesday at Camden Yards -- just one day removed from Rodriguez exiting his start for Triple-A Norfolk with what was deemed, at the time, to be right lat discomfort. Rodriguez reported to Baltimore on Thursday morning where visits with team doctors revealed the more serious ailment.

The severity of the strain is not yet known, as Rodriguez will receive a second opinion and undergo additional testing. There is no exact timetable for a return, other than “safe to say he'll miss some time,” Elias said.

“The timing of this stinks,” Elias said. “We were watching every start of his very carefully, and carefully building him toward readiness -- from a workload standpoint, from a everything-you-can-think-of standpoint -- to what's going to be a very long and fruitful pitching career. Obviously, this is a delay.”

Breathing confidence for the Orioles is that this is a muscular strain, with nothing found as far as structural damage to the shoulder, rotator cuff or labrum area, Elias said. But caution will be exerted for Rodriguez, the O’s No. 2 prospect who’s already been under an especially watchful eye across his five years in the organization.

“Certainly a 22-year-old on the front-end of his career, I think it puts any kind of calculus toward the longest-term considerations rather than rushing back. I think that goes without saying,” Elias said. “ … It's not something that I think, at this point in time, looks particularly worrisome from a long-term standpoint, and we've had guys pull muscles all the time. But it's an unfortunate timing development for both him and the Orioles, obviously.”

Rodriguez had thrown just 63 pitches across 5 2/3 innings for Norfolk on Wednesday before he was paid a visit from manager Buck Britton and pitching coach Justin Ramsey on the mound. After a lengthy discussion, Rodriguez walked off with a trainer. There was no indication of anything bothering Rodriguez in his recent starts, Elias said; Wednesday was “sort of a precipitous feeling that he had.”

It’s a wholly untimely injury for Rodriguez, the Orioles’ top pick in the 2018 Draft, who has compiled a 2.09 ERA in his first 11 starts at the Triple-A level. Recent results were even more promising, with Rodriguez owning a 0.79 ERA and 47 strikeouts across his last six outings.

Such performances were pushing the question of how much longer it would take before Rodriguez joined batterymate Adley Rutschman in Baltimore. Now, the timeline is far murkier.

“I don't have any ability to speak on the timetable of this right now,” Elias said. “I'm trying to get as much info out as possible as soon as possible given the high-profile nature of the injury. … But it's something that time should rectify at some point.

“Certainly very disappointing development in terms of the 2022 calendar and our hopes and his, but it's something that we’ll ultimately get through.”