PORT ST. LUCIE, Fla. - The Mets had a change of heart Saturday, sending pitcher Zack Wheeler for an MRI exam on his sore right elbow, just one day after general manager Sandy Alderson said it would not be necessary.

Manager Terry Collins said the results have yet to be reviewed, but revealed that Wheeler underwent a pair of MRIs this offseason that came back negative for structural damage.

"It's always a precaution," Collins said.

While team officials believe Wheeler's elbow soreness won't be a lingering issue, the episode stands as a reminder of the precarious position the Mets could face.

Wheeler, 24, is one of the crown jewels of perhaps the deepest and most talented core of young pitchers in all of baseball. For the Mets, though, all that firepower also means risk.

"There's a risk, risk-reward, as far as these young power pitchers," Mets captain David Wright said. "It's max effort. It's a lot of wear and tear on your arm. When they're healthy, they're dynamite. But obviously, with that strain that puts on your arm, that torque that it takes . . . you know that chances are you're going to have an arm problem or two during spring training."

Wheeler emerged as the latest example. The tenderness in his right elbow has come and gone through the years. Even Wheeler admitted that if this were the regular season, he would probably keep pitching, just as he did last year.

In spring training, however, the results carry no weight. Which is the only reason that the Mets righthander insists he will be rested for only a few days, until the sensation subsides.

"It's spring training," said Wheeler, who was scratched from his scheduled start Saturday. "You don't want to push yourself during spring training. And the games don't mean anything here. I'm trying to get myself right for the season when the games actually do mean something."

Wheeler has been plagued by two separate issues in recent days.

The first is a blister beneath the nail of his middle finger, a condition that has popped up regularly since his days of pitching in high school. It is at most a nuisance, cleared up with time and medication.

The second issue -- recurring soreness in his right elbow -- raises red flags.

"It's something that I've had before and have had to deal with," said Wheeler, who is expected to take his next turn in the rotation, which falls on Thursday.

At the very least, Wheeler's situation has called attention to the blurry lines that exist when it comes to developing pitchers. At what point does pitching through typical aches and pains become pitching through injuries? What's the difference between learning to handle a big-league workload and pushing too far into a danger zone?

Even as he downplayed the elbow issue, Wheeler admitted he hasn't totally divorced himself from it.

"You always have that in the back of your head," Wheeler said. "But you try not to change anything you're doing -- arm angle, mechanics, all that kind of stuff. You do what you've been doing and trust it."

Both the Mets and Wheeler insist that intermittent soreness had no impact on the pitcher's performance last season. That's when Wheeler was 11-11 with a 3.54 ERA while stringing together a dominating second half that signaled a step forward in his development as a pitcher.

He did it with a crackling fastball that averaged 94.7 mph -- the sixth fastest among all qualifying pitchers in baseball.

"Every pitcher in here pitches through pain at some point, so it's just a matter of dealing with it and going out there," Wheeler said. "It wasn't affecting me all that much so I could go out there and compete like I wanted to. So, I was going to do it."

Nearly half of Wheeler's starts (14) last season came with at least one extra day of rest. But he threw 100 pitches in all but eight of his 32 starts. That workload included examples of pitching through elbow discomfort, according to Collins.

"There were a lot of games he pitched with his elbow bothering him," Collins said. "So we know it's been there. We know he's had this issue before. That's why I'm very glad he spoke up now because we've got enough time to back him up a little bit and still get him to where he needs to be. I'm glad he said something."

Nevertheless, Collins mentioned that Wheeler wants to reach the 200-innings mark this season. And Wheeler himself didn't mind the measures needed to handle last season's workload.

"Anti-inflammatories, treatment, all kinds of stuff," Wheeler said. "And just deal with the pain, just going out there and pitching through it."

Of course, there are plenty of warning signs around the Mets' clubhouse.

Matt Harvey is just now emerging from the other side of a 171/2-month rehab process including Tommy John surgery. Both Rookie of the Year Jacob deGrom and promising prospect Steven Matz underwent ligament replacement surgery early in their careers.

Wheeler has avoided such a fate. But clearly he has not been exempt from the ravages of pitching. He insisted Saturday that he never received a cortisone shot to mask the pain in his elbow last year.

Nor did he have to cut down on his work between outings.

"I threw every bullpen last year," Wheeler said. "I pitched every game."

But the question lingers: Will Wheeler be able to say the same at season's end?

"He has such tremendous torque on his arm," Collins said, almost ominously. "There's always going to be issues."