SURPRISE, Ariz. — When Jacob deGrom stepped on the mound for his first live batting practice this spring, a voice in his head told him: “All right, I want to strike everybody out.” That instinct had guided deGrom to unimaginable heights, with awards and money and acclaim. It is also who he can no longer be. So deGrom took a breath and reminded himself: “Let’s not do that.”

Nobody in the world has ever thrown a baseball like deGrom at his apex. His combination of fastball velocity, swing-and-miss stuff and pinpoint command led to one of the greatest 90-start stretches in baseball. From the beginning of 2018 to the middle of 2021, he was peak Pedro Martinez with a couple of extra mph — Nolan Ryan’s fastball, Steve Carlton’s slider, Greg Maddux’s precision.

Then his arm could not hold up anymore, and for more than three years, deGrom healed and got hurt, healed and needed Tommy John surgery in June 2023 to repair the ulnar collateral ligament in his right elbow, then healed once more. That delivers him to this moment, in camp with the Texas Rangers, ready to conquer a 162-game season for the first time since 2019 — and reminding himself when to hold back.

The instinct to be all he can be never will go away. But instead, as his efforts at learning to throttle down manifest themselves daily and were particularly evident in those early live ABs, deGrom induced ground balls on early contact and ended his day with a flyout on the second pitch of the at-bat.

DeGrom had blown out his elbow once before, as a minor leaguer in October 2010, and this time he understands his mandate. He is now 36, and nobody has returned to have any sort of substantive career after a third Tommy John, so keeping his arm healthy as he comes back from his second is imperative. This is the last phase of deGrom’s career, and to maximize it, he must change. It does not need to be a wholesale reinvention. For deGrom, it is more an evolution, one to which he accustomed himself by watching video of his past self.

DeGrom at his best simply overwhelmed hitters. At-bats turned into lost causes. He was the best pitcher in the world in 2018, when he threw 217 innings of 1.70 ERA ball and struck out 269 with just 46 walks and 10 home runs allowed. The following year, he dedicated himself to being even more, winning his second Cy Young and proving he was no one-season fluke. DeGrom routinely blew away one hitter, then made the next look like he’d never seen a slider. He painted the plate with the meticulousness of a ceramic artist.

“I look at the best — ’18,” deGrom said of his first Cy Young season. “There were times where I hit 100 or close to it, but I think I sat around 96.”

He did. Ninety-six mph on the dot for his high-spin four-seam fastball. It jumped to 96.9 in 2019, 98.6 in 2020 and 99.2 in 2021. In the 11 games deGrom pitched toward the end of 2022, it was still 98.9 — and then 98.7 before he blew out again.

“I have to look at it like, hey, I can pitch at that velocity [from 2018],” deGrom said. “It is less stress on your body. You get out there and you’re throwing pitches at 100 miles an hour for however many pitches it is — it’s a lot of stress. It’s something that I’m going to look into — using it when I need it, backing off and just trusting that I can locate the ball.”

He had not yet adopted that attitude in 2022, when those 11 starts convinced deGrom to opt out of his contract with the New York Mets, who had drafted him in the ninth round in 2010. Immediately, the Texas Rangers began their pursuit. General manager Chris Young pitched for 13 years in the major leagues and knows how hard it is to be truly great. He grunted to hit 90 with his fastball. Someone who could sit 99 with 248 strikeouts against 19 walks in 156⅓ innings (as deGrom did in the combined pieces of his 2021 and 2022 seasons) and make it look easy is one of a kind. Injury risk be damned, Texas gave deGrom $185 million over five years.

He played the part in his first five starts for Texas. Then he left the sixth with elbow pain. Done for the year. Surgery on June 12 — 11 days after the birth of his third child, Nolan. He carried Nolan around with his left arm while his right was in a brace that would click a degree or two more every day to eventually reteach deGrom to straighten his arm.

He taught himself how to throw again, too, under the watchful eyes of Texas’ training staff and Keith Meister, the noted Tommy John surgeon who is also the Rangers’ team doctor. They wanted to build back the deGrom who scythed lineups — but this time, with decision-making processes guided by proper arm care.

Part of that showed in deGrom’s September cameo last year. His fastball averaged 97.3 mph, and he still managed to look like himself: 1.69 ERA, 14 strikeouts against one walk with one home run allowed in 10⅔ innings. Rather than rush back, deGrom put himself in a position to tackle the offseason. Those innings were enough to psychologically move past the rehabilitative stage and reenter achievement mode. He trained with the same intensity he did in past seasons. The stuff would still be there. While peers were spending the winter immersed in pitch design, deGrom was seeking the version of himself that could marry his inherent deGromness with the sturdiness he embodied the first six years of his career.

“I wasn’t trying to build anything in a lab,” deGrom said. “My arm got a little long a few years ago, so trying to shorten up the arm path a little bit and sync up my mechanics really well is what I’ve been trying to do.”

Rather than jump out in the first start of the spring to prove that heartiness, deGrom took his time. It is a long season. He wants to be there in the end. His goal for this year is straightforward: “Make as many starts as I can.” If that means throwing live at-bats a little longer than his teammates, that’s what he’ll do. Ultimately, deGrom is the one who defines his comfort, and he went so long without it that its priority is notable.

So if that means shorter starts early in the season, it won’t surprise anyone. There is no official innings limit on deGrom. The Rangers, though, are going to monitor his usage, and he doesn’t plan to use those limited outings to amp up his velocity. This is about being smart and considering more than raw pitch counts or innings totals.

“I think it’s going to be a monitor of stressful innings versus not,” deGrom said. “You have those games where you go five innings, you have 75 pitches, but you’ve got runners all over the place, so those are stressful. Whereas you cruise and you end up throwing 100 pitches and you had one or two runners. It’s like, OK, those don’t seem to be as stressful. So I think it’s monitoring all of that and just playing it by ear how the season goes.”

That approach carried into deGrom’s spring debut Saturday against the Kansas City Royals. He averaged 97 mph on his fastball, topping out at 98. His slider remained near its previous levels at 90. He flipped in a pair of curveballs for strikes, too, just as a reminder that he’s liable to buckle your knees at any given moment. On 31 pitches, deGrom threw 21 strikes, didn’t allow a baserunner and punched out three, including reigning MVP runner-up Bobby Witt Jr. on a vicious 91.5-mph slider.

On his last batter of the day, deGrom started with a slider well off the plate inducing a swing-and-miss from Tyler Gentry, then followed with a low-and-not-quite-as-outside slider Gentry spit on. When a curveball that was well off the plate was called a strike, deGrom saw an opportunity. This is the art of pitching — of weighing the count, what a hitter has seen, how to take advantage of an umpire’s zone. He dotted a 97.3-mph fastball on the exact horizontal plane as the curveball and elevated it to the top of the strike zone, a nasty bit of sorcery that only a handful of pitchers on the planet can execute at deGrom’s level. Gentry stared at it, plate umpire Pete Talkington punched him out and deGrom strode off the mound, beta test complete.

“It’s always a thing of trusting your stuff,” deGrom said. “It’s one of the hardest things to do in this game, and part of it’s the fear of failure. You throw a pitch at 93 when you could have thrown it at 98 and it’s a homer, you’re like, ‘Why did I do that?’ So that’s the part that gets tough. You still have to go out there and trust your stuff, know that you can locate and change speeds, and still get outs not full tilt the whole time.”

Day by day, deGrom inches closer to that. He’ll get a little extra time, with the likelihood the Rangers will hold him back until the season’s fifth game, just to build in rest before the grind of a new season. He’s ready. It has been too long since he has been on the field regularly, contributing, searching for the best version of himself. It might look a little different. And if it does, that’s a good thing.