JUPITER, Fla. -- Suddenly there is urgency for the Mets to replace Jose Quintana in their starting rotation, possibly for an extended period of time, and the good news for them is that Tylor Megill is offering evidence he can return to the dominant form he showed last April before a shoulder injury essentially ruined his season.

Megill threw four scoreless innings against the Marlins here on Monday, and while he’s not throwing his fastball in the high 90s as he did before his injury, Buck Showalter said he can see a return to dominance.

“It’s nice to see him on his way back to where he was last year when we broke camp,” Showalter said. “He was one of the best pitchers in the league for a month or so before he got hurt. So he’s a lot more than depth for us.”

Megill isn’t necessarily penciled in yet as the new No. 5 starter. He and David Peterson are competing for that spot, and Showalter spoke very highly of the lefthander as well.

For that matter, the Mets could need both of them, after Kodai Senga missed a start Saturday due to tendinitis in the finger of his throwing hand. However, Showalter was encouraged on Monday that the injury won’t keep him out long after he threw on flat ground without a problem.

As for Quintana, GM Billy Eppler responded to a published report saying Quintana would be shut down for three months by calling it “premature.”

“We don’t have all the information yet,” Eppler said outside the visiting clubhouse after Monday’s game. “I was on the phone today with more doctors, and with Jose. And it’s just premature. I want to make sure we have this buttoned up, and have Jose’s opinion, and go from there.”

Eppler indicated that as many as five doctors have either examined Quintana or been consulted to get the proper diagnosis after the lefthander suffered a stress fracture on the fifth rib on his left side. The GM said he hoped to have a firm diagnosis to announce by Wednesday.

At the very least, however, it seems clear Quintana is going to miss significant time. As such the opportunity is there for Megill, which at least one major league scout told me could be “a blessing in disguise” for the Mets.

“If they get him right again, he’s a better option than Quintana,” the scout said. “If he gains a little more of his velocity back, he could be the guy we saw last year. And you could see today he’s learning how to use his secondary stuff better than he did in the past.”

Velocity may be something of a tricky issue for Megill. After topping out at 95 mph Monday and throwing mostly in the 93-94 mph range, he admitted that his desire to throw harder during his early dominance last season may have contributed to his shoulder injury.

“That’s why I’m pulling my foot off the gas a little bit, to stay healthy,” he said.

Or as Showalter put it, “He learned more is not always better.”

Injury concerns aside, Megill is pitching with a different mindset as well, determined to pitch deeper into games, in part because of watching the way Max Scherzer worked as a Met last year and talking to him about his success over the years.

“He’s had a long, healthy career and he’s able to save some in the gas tank for when he needs it to go the distance,” Megill said. “That’s what I’m trying to do. Last year I’d throw 97, 98, 99 in the first couple of innings, then my velo would trickle down. I’d use all my bullets. Now I’m trying to save my bullets and stay fresh longer.”

Scherzer, meanwhile, pitched in a minor league game on a back field here on Monday because, with a nod toward Quintana’s injury, he thought it was important that Megill face the Marlins’ major league lineup.

“We need him to get up to speed,” was the way he put it.

Furthermore, Scherzer seems to have taken a special interest in Megill, mentoring him about how to make the most of his stuff. It’s no accident that Megill has been working hard this spring to implement a slow curve ball into his repertoire, something Scherzer has always done as a way of keeping hitters off balance and preserving arm strength.

“He was a guy who would empty the tank early in the game,” Scherzer said. “He wasn’t able to get to 100 pitches and be strong at 100 pitches.

“So in my conversations with him I said, ‘You want to be strong at 100 -- that’s where you win or lose ballgames.’ Hopefully he’s taking that to heart and harnessing it if he can.”

Megill said that indeed he has, noting that the off-speed stuff is important as a way of keeping hitters honest against his fastball.

“I threw a lot of strikes with the off-speed stuff today,” he said. “I think it’s really going to help me at the top of the zone. The metrics show that my fastball is playing the same way as it did when it was firmer and come the season my velo should pick up some more. So I feel good about where I am.”

And then there was one last change he made, dropping 15 pounds, in part because pitching coach Jeremy Hefner stressed the importance of being in condition to pitch more quickly, as dictated by the pitch clock.

“Had to get in shape for the pitch clock,” Megill said with a smile.

All the changes seem to be paying off, at least for now. And suddenly that’s not just a pleasant development for the Mets. It could be vital.