Steven Matz of the New York Mets sits in the...

Steven Matz of the New York Mets sits in the dugout after he was removed from a game against the Miami Marlins during the second inning at Citi Field on Monday, April 11, 2016. Credit: Jim McIsaac

WASHINGTON — Mets lefthander Steven Matz could be facing elbow surgery — during the offseason or perhaps even sooner — to treat a bone spur that has forced him to deal with lingering discomfort, multiple sources told Newsday on Monday.

General manager Sandy Alderson will be part of a meeting with Matz on Tuesday to decide how to proceed.

Early in his career, Matz underwent Tommy John surgery and endured a bumpy rehab that essentially cost him nearly two years. But according to a source, Matz’s bone spur is not in an area that “poses a threat to the ligament,” which is a sliver of encouraging news.

While an MRI exam on Monday in New York revealed that there are no issues with the ligament, and the rest of Matz’s elbow appears structurally sound, the bone spur is causing pain, which itself has proved to be a complication.

Some within the organization are concerned that the discomfort has impacted Matz’s ability to compete effectively, impeding his ability to throw his breaking pitches. So in-season surgery at least will be “part of the conversation,” according to a source, even though there is a belief that pitching through the pain won’t make the injury worse.

“He’s not pitching good, that’s the issue,” manager Terry Collins said. “The reports are he can handle the discomfort, probably. There’s no structural damage. But you’ve got to pitch good.”

Matz himself did not divulge the specifics of his diagnosis, but the Long Island native did acknowledge pitching through elbow discomfort. He also revealed that doctors have advised him that rest alone would not do anything to lessen the pain in his elbow.

The Mets have two choices: Matz can undergo surgery soon, which might sideline him until September, or he can keep pitching, manage the pain and delay surgery until the season is over.

“I know the peace of mind that there is nothing structurally wrong,” said Matz, who is 7-3 with a 3.29 ERA, though his performances have trended downward in the last month. “And the doctor said the ligament and everything was great, so that peace of mind is great to have . . . It’s just something that I’m going to have to battle through.”

Bone spurs are common among pitchers, who often endure the side effects in order to postpone surgery until after a season, though that is a matter of pain tolerance.

Matz was scheduled to start on Wednesday, but his status won’t be determined until after Tuesday’s meeting. Logan Verrett would be in line to start in his place, if necessary.

It’s unclear how long the Mets have been aware of Matz’s bone spur, but in May, elbow tightness forced one of his starts to be bumped back. Tests then also did not show ligament issues.

Matz complained of elbow tightness after his start on Friday, when he nearly coughed up an 8-0 lead, allowing six runs while getting chased in the fifth.

Matz acknowledged that he was unable to properly finish his pitches, though he stopped short of pinning it on his elbow tightness.

Said Matz: “It’s hard for me to say.”