NEW YORK -- The Mets’ starting rotation suffered another significant blow on Monday, when an MRI revealed that Joey Lucchesi has a significant UCL tear in his left elbow. Tommy John surgery is a realistic option for Lucchesi, who will receive a second opinion before making that decision.

The news hit during the best stretch of Lucchesi’s season, which included a 1.19 ERA over his last five starts. Following his most recent outing, in which he delivered 5 1/3 shutout innings on Friday, Lucchesi complained of left elbow soreness. The Mets subsequently placed him on the injured list and scheduled him for an MRI. Only Monday did team officials learn of the torn ligament -- an injury that almost always requires Tommy John surgery when significant. Regardless, Lucchesi will seek a second opinion to be sure there is no way to avoid the operation.

“Even though that’s the first thing that comes to mind about having the surgery, he wanted -- and we wanted -- to hear a second opinion on it,” manager Luis Rojas said.

Overall, Lucchesi was 1-4 with a 4.46 ERA in his first season with the Mets, who acquired him from the Padres in a three-team deal last winter.

If Lucchesi does opt for Tommy John surgery, he will miss the rest of this season and most or all of next season, as well. The operation typically requires a rehab period of 12-18 months.

“It’s a big loss for us,” Rojas said. “A talented young kid that I think is just getting better every time he goes out there. Let’s see what comes out of this. The second opinion will let us know for sure what the decision’s going to be.”

Even with a healthy Lucchesi, the Mets were already considering upgrading their rotation before the July 30 Trade Deadline, considering they have also played this entire season without Noah Syndergaard (recovery from Tommy John surgery) and Carlos Carrasco (torn right hamstring). With those two and Jordan Yamamoto (right shoulder soreness) all sidelined, dealing for another starter now appears to be a near-certainty. Top starters available could include Kyle Gibson of the Rangers, Jon Gray and Germán Márquez of the Rockies and Luis Castillo of the Reds.

In the short term, the Mets, who are in the midst of three doubleheaders in seven days, do not boast many experienced in-house options. Veteran Jerad Eickhoff made his season debut in the Mets' 1-0 loss in Game 2 of Monday’s doubleheader against the Braves, while two other starters -- Nick Tropeano and No. 10 prospect Thomas Szapucki -- are on the organization’s 40-man roster. The Mets will need to use some combination of those pitchers, while also relying heavily on their bullpen, to stay afloat as they move closer to the Trade Deadline.

“It’s a challenge once again,” Rojas said. “This is a baseball season. It’s full of challenges. You have it with the injuries. You have it with the ups and downs of some guys throughout the season, and you have it facing the other teams, really good teams that you’re playing. So there’s challenges everywhere. We’re meeting this one right now.”