PORT ST. LUCIE, Fla. -- It is technically still possible that Jacob deGrom starts Opening Day, the Mets say. But with only 25 calendar flips to go, it appears unlikely deGrom will pass enough tests to make that a reality.
Throwing a 40-pitch bullpen session Sunday, deGrom experienced no ill effects from the back stiffness that sidelined him for several days last month. But he has yet to face live hitters, which he is scheduled to do for the first time Tuesday in a simulated game. Mets pitching coach Dave Eiland said deGrom will need to face batters at least five times before he starts a regular-season game, making an Opening Day assignment impossible unless deGrom completes a limited enough workload in his sim game to return on short rest for the first of four Grapefruit League starts.
In other words, unlikely. And five times facing hitters isn't just a recommendation. It's a requirement.
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"With Jacob deGrom, we will not make an exception," Eiland said. "That's stupid. We're not going to be careless. We're not going to be careless just so he can pitch Opening Day. If it falls where he can, he will because he earned it. He deserves that start. But we're not going to push the envelope and be careless, and he starts Opening Day and doesn't start again until June. That would be pretty ignorant on our part."
Although deGrom says he would appreciate the honor of making his first career Opening Day start, he will be happy as long as he debuts during the Mets' first rotation turn -- something he is still in line to do.
"I would definitely like to start Opening Day, but that's out of my control," deGrom said. "It's kind of up to them."
Entering camp, it seemed a foregone conclusion that deGrom, who set career highs in starts, innings and strikeouts last season, would become the Mets' eighth different Opening Day starter in the last eight years. Finishing eighth in National League Cy Young Award voting last season, deGrom went 15-10 with a 3.53 ERA.
But when he resumed throwing following three days off for the birth of his daughter in mid-February, deGrom experienced a bout of back stiffness. Though minor, the episode sidelined him long enough to put Opening Day in jeopardy.

Since then, the Mets have proceeded carefully with deGrom, asking him to play catch multiple times, to throw a modified bullpen session off the slope of a mound and finally to complete Sunday's 40-pitch session before facing hitters.
"It's in steps. It's in stages," Eiland said. "Every one of these days is a hurdle we have to clear before we move onto the next one."
Added deGrom: "The plan is not to do anything dumb."
Even if deGrom does not pitch Opening Day, he should be ready to start the Mets' second game of the season two days later. In that case, Noah Syndergaard would become the obvious candidate to start the opener, becoming the first Mets pitcher to do so in consecutive years since Johan Santana from 2008-10.
"If I don't start Opening Day, it's not the end of the world," deGrom said. "The goal is to go out there and make every start once the season starts. Whether it's Opening Day that I start, or it's the third, fourth, fifth day, the goal is just to make every one of them. ... It would definitely be an honor to start it. But if I don't, then I don't."