Mets pitcher Jose Quintana during a spring training game against...

Mets pitcher Jose Quintana during a spring training game against the Houston Astros, Tuesday Feb. 28, 2023 at Clover Field in Port St. Lucie, FL. Credit: Newsday/Alejandra Villa Loarca

PORT ST. LUCIE, Fla. — The Mets have suffered their first noteworthy injury of spring training.

Jose Quintana has a “small stress fracture” in the fifth rib on his left side, the team announced Monday night. He will travel to New York for additional tests.

The Mets did not provide a timeline for Quintana’s expected return, but with Opening Day about three weeks away, he appears highly likely to miss the start of the season.

A rib stress fracture usually is a week-to-week situation at best, according to Dr. Spencer Stein, a sports orthopedic surgeon for NYU Langone Orthopedics, who spoke about this type of injury generally and not Quintana’s case specifically.

The problem is “on the rare side,” he said, but when it happens, it usually happens to pitchers. The best course of treatment is rest.

“It’s a repetitive, overuse injury. Pitchers get these kinds of torso injuries. You think of oblique strains, which are more commonly reported,” Stein said, citing the torque created by a standard pitching motion. “With any type of stress fracture, you typically let it heal. The bone will heal. Usually it’s some sort of non-weight-bearing or immobilization. But the tricky thing with ribs is you can’t really immobilize it. You can’t cast a rib. And every time they breathe, they’re putting a little stress on it. The answer to treatment is: It’s rest, it’s time, it’s not throwing.”

Quintana complained of tightness in his left side Sunday, so the Mets removed him from his outing against the Cardinals after he threw 13 pitches in a 1-2-3 third inning. None of his three career trips to the injured list have been for any sort of side/rib issue.

A recurrence of the injury is “something to watch” with any stress fracture, but overall, pitchers make a full recovery, Stein said.

“It’s overall a good prognosis,” he added.

The Mets prepared for this by designing their offseason pitching plan around the inevitability of injuries, especially given the age of the rotation members.

They acquired three major-league starters — Quintana, plus Justin Verlander and Kodai Senga — and pushed David Peterson, Tylor Megill, Joey Lucchesi and others down the depth chart.

However long Quintana is out, the Mets will have to rely on one of their backups.

Peterson was the best of that bunch in 2022, posting a 3.83 ERA and 1.33 WHIP in 28 games (19 starts). He had his own scare over the weekend, taking a comebacker off the outside of his left foot, but is considered day-to-day after being diagnosed with just a bruise.

Megill was the sixth starter to start last season, winding up with the Opening Day assignment after Jacob deGrom got hurt. He started strong, then struggled before injuring his shoulder. He had a 5.13 ERA and 1.25 WHIP in 15 games (nine starts).

Peterson and Megill entered camp as starting pitchers penciled in for Triple-A Syracuse, not candidates for the bullpen.

“He’s going to get the opportunity,” manager Buck Showalter said of Peterson early in spring training. “I wish it was a little more clear-cut right now, but he’s going to get the opportunity.

“Does he think he can pitch in the big leagues right now? And Tylor? Yeah, of course they do. You want them to. I think they’re mature enough and have been around [enough] to know how quickly things can change. They’ve got to be ready. At some point, the doors are going to open and the curtains are coming back and they’re going to get their opportunity. They did last year. They took good advantage of it. It’s why they’re still here and we think highly of them.”

Part of what attracted the Mets to Quintana, 34, during the offseason was his durability. He’s made at least 31 starts in eight of the past nine full seasons.

That made him look like a relative sure thing, from an availability point of view, in a rotation that has age concerns. Verlander is 40 years old, Max Scherzer turns 39 in July and Carlos Carrasco will be 36 on March 21. Senga, a rookie from Japan, is the youngest at 30.

Quintana finished last year with a career-best 2.93 ERA, particularly effective after a midseason trade to the Cardinals. The Mets rewarded him with a two-year, $26 million contract to help solidify the back of their rotation.

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