ST. LOUIS -- Although Jacob deGrom is progressing in his road back from a right shoulder injury, the timeline for his return remains as murky as ever.

An MRI scan taken Monday of deGrom’s right shoulder revealed “considerable healing of the stress reaction on his scapula,” according to a team release. Mets doctors cleared deGrom “to begin loading and strengthening of the shoulder,” which he must do before he begins throwing.

But team officials offered no indication of when deGrom might actually pick up a baseball and restart a throwing program. One person with knowledge of the situation noted that deGrom must ramp up in phases, with the “loading and strengthening” phase preceding a throwing program.

Throwing -- whenever it occurs -- will represent a more significant test, and only once that phase begins will deGrom’s timeline become clearer. He will receive another MRI in approximately three weeks. If deGrom does not pick up a baseball until that point, it’s unlikely he will be able to rejoin the Mets until at least mid-June. But he could require more or less time, depending upon how he recovers.

So continues the saga of arguably the game’s best pitcher, who has not appeared in a Major League game since last July 7. Around that time, deGrom began experiencing the elbow issues that haunted him for the rest of the season. He rested over the offseason and reported to Spring Training healthy, but deGrom began suffering shoulder discomfort following his second Grapefruit League start on March 27. A subsequent MRI revealed a stress reaction on his scapula -- an overuse injury that required about a month of rest.

Monday’s MRI was a follow-up on the initial test that deGrom received in late March. deGrom also received a CT scan last week on his shoulder.

When healthy over the last four seasons, deGrom has been peerless, with a 1.94 ERA and 774 strikeouts over 581 innings -- a resume that includes two NL Cy Young Awards. But health has been difficult for deGrom to maintain; since 2020, he has missed time due to shoulder, elbow, forearm, back and lat issues.

Earlier on Monday, Mets manager Buck Showalter said he has not spoken to deGrom since shortly after Opening Day. Outside of a brief trip to New York to be with the Mets at their home opener on April 15, deGrom has spent most of his time resting and rehabbing in Florida.

“He doesn’t like that constant banter,” Showalter said. “When he gets to where he’s throwing, he’ll join us. It’s pretty simple.”

Despite deGrom’s absence, the Mets have managed to construct one of the best records in the Major Leagues, thanks in large part to a rotation that has produced a 2.29 ERA without him. deGrom’s direct rotation replacement, Tylor Megill, has shined, going 3-0 with a 2.35 ERA in four starts.