PORT ST. LUCIE, Fla. — Steven Matz has been scratched from his scheduled start Monday with tenderness and irritation in his left elbow, Mets general manager Sandy Alderson announced Sunday.

Doctors have reassured Matz that he has no ligament damage, a relief for a pitcher who already has had Tommy John surgery. But with the Mets a week from Opening Day, the development could force them to dip into their rotation depth.

Matz said he’s not concerned about the setback and expects to resume throwing Monday. He felt tenderness before his last outing Wednesday. When the soreness during the game persisted, he alerted the Mets.

“I talked to the doctor right away just to see his thoughts,” said Matz, who had a bone spur removed from his elbow after a shoulder issue ended his 2016 season. “He just said this stuff can happen when you’re coming back from surgery.”

Matz, who made his big-league debut in 2015, is 13-8 with a 3.16 ERA in 28 starts. Both of his seasons in the majors have been plagued by injuries, continuing a pattern he established in the minor leagues.

“It’s worrisome that he continues to be off and on, that’s the difficulty,” Alderson said of the Long Island native. “As I said, we don’t think it’s serious. But on the other hand, we have to be able to [rely on starting pitchers] every five days.”

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Matz has yet to be sent for an MRI exam or been given any painkilling injections, Alderson said, though his medication has been adjusted. Elbow tenderness persists when Matz attempts to get extension on his pitches.

“We’re just not going to know for the next two or three days,” Alderson said.

Righthanders Zack Wheeler and Seth Lugo will pitch in the Mets’ split-squad games Monday. Both are contenders to slot into the starting rotation if needed, with Robert Gsellman looking as if he already has locked up a spot.

Wheeler missed the last two seasons after Tommy John surgery. Though he has an 8.59 ERA in camp, he has hit 97 mph with his fastball, a sign that he is healthy. His performance has vaulted him into the mix after team officials initially believed he was ticketed for extended spring training.

Lugo had a 4.20 ERA in 15 innings during the World Baseball Classic. He was the starting pitcher in Puerto Rico’s loss to the United States in the WBC final.

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“We’re still sorting through that,” Alderson said of the Mets’ options. “Fortunately, Zack Wheeler is coming along. Gsellman’s pitched very well. Lugo pitched well in the World Baseball Classic. So yes, this is where depth comes into play.”

Matz had been scheduled to pitch in a minor-league game Monday. He looked to turn the page on a poor outing that raised his ERA to 4.26.

For now, Alderson insists the setback isn’t major.

“The doctors have examined everything,” he said. “We’re not concerned about that at the moment. He’s not pitching tomorrow. That’s really the purpose of this conversation rather than writing an epitaph.”

The Mets restructured the typical spring training schedules for all of their pitchers. They restricted throwing during drills early in camp and pushed back game appearances by about a week for the pitchers projected to make the starting rotation.

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Matz, 25, insisted he benefited from the new throwing program. When he felt his elbow flare up before his last outing, he wasn’t concerned enough to mention it to trainers.

“I’m feeling good,” he said shortly after his last outing. “I’m glad I’ve got one more start.”

But by then, he already had alerted trainers about his balky elbow.

The Mets have five exhibition games remaining through Wednesday. On Thursday, the Mets will play their Triple-A Las Vegas affiliate before hosting a game Friday at Citi Field against Army. After that, Matz’s only opportunity for game action might come against minor-leaguers in Florida.

His throwing Monday will consist of long toss, the first step in getting back on the mound.