SCOTTSDALE, Ariz. — Zac Gallen had just been promoted to Class AA, and his first assignment for the Springfield Cardinals was to chart the pitches of a teammate. It was a routine task and Gallen was tired, but a coach gave him a tip: “You might want to pay attention to this.”

The “this” in question was Sandy Alcantara in 2017, a few months before he and Gallen would be traded from the St. Louis organization to Miami for outfielder Marcell Ozuna. Alcantara, a willowy right-hander from the Dominican Republic, was throwing 97 to 102 miles per hour, Gallen recalled, working to refine his secondary pitches but clearly a name to remember.

Last season, Alcantara was the unanimous National League Cy Young Award winner for the Marlins. He had all the indications of a breakout candidate hiding in plain sight: durability, performance, relative anonymity and youth.

Entering 2022, Alcantara was coming off a season in which he surpassed 30 starts and 180 innings and had an E.R.A. under 3.50. He had never pitched in the World Series or finished in the top three in Cy Young voting, and was no more than 27 years old.

Two N.L. pitchers meet that criteria for 2023: Gallen, who is now with the Arizona Diamondbacks, and Logan Webb of the San Francisco Giants. Don’t be surprised to see them challenge Alcantara for the next N.L. Cy Young Award.

Zac Gallen

Zac Gallen woke up a winner on his 27th birthday, last Aug. 3, but it wasn’t an especially impressive victory: He had allowed three runs in five and two thirds innings the previous night in Cleveland. For Gallen, it was more of the same, the last in a stretch of 13 starts in which he had a 4.50 E.R.A.

Gallen, a cerebral right-hander from the University of North Carolina, mapped out the rest of his season. In each of his remaining starts, he resolved, he would work at least seven innings and allow no more than one earned run. Then he could finish with an E.R.A. under 3.00.

He didn’t allow a run until 40 days later.

Gallen pitched shutout ball in each of his next six starts, extending his scoreless streak to 44 ⅓ innings until the fourth inning of a start in Colorado on Sept. 11. It was the seventh longest scoreless streak in major league history, 15 innings behind Orel Hershiser’s record in 1988. Gallen’s instinct was to shy away from the attention.

“But at the same time,” he said, “I’m thinking, ‘I’ve got to lean into this, because there’s been guys with way better careers than me and they’ve gotten to 35 innings and done it one time. This may never happen again, so I have to embrace it.’ And it really still hasn’t set in; honestly, I don’t know if it ever will. It was a lot of fun, though.”

Gallen ended up with the lowest WHIP (walks plus hits per inning pitched) in the N.L., at 0.913, and allowed just 5.9 hits per nine innings, the fewest in the majors. To his teammates, the streak seemed almost inevitable.

“It was one of those things where you’re like, ‘Wow, what a cool thing’ — but in the same sense, you’re not surprised,” first baseman Christian Walker said. “Look at the way he carries himself, look at the standard he sets for himself. He’s hard on himself, but in a good way, in a motivating, get-the-best-out-of-yourself kind of way.”

Gallen uses five pitches (fastball, curveball, changeup, slider, cutter) and Brent Strom, the Diamondbacks’ veteran pitching coach, sometimes implores him to simplify his arsenal. But it works for Gallen, who has fulfilled every hope the Diamondbacks had when they acquired him — after just seven major league starts — in a July 2019 trade for Jazz Chisolm Jr., a top prospect who is now an All-Star for Miami.

“They were trying to push us off Gallen and we were trying to push them off Jazz,” Arizona General Manager Mike Hazen said. “They came to us with some ideas on ‘Jazz for X,’ and we would come back with ‘Gallen for Y.’ We loved Jazz, and clearly he’s turned into an exceptional player. But we were trying to acquire starting pitching and Zac was one of the top guys. It’s worked out for both sides.”

The Diamondbacks this month signed an offensive cornerstone, the rookie outfielder Corbin Carroll, to a $111 million contract that could tie him to the team through 2031. Gallen is represented by Scott Boras, who usually takes clients to free agency, but he has three more years under club control to try to help Arizona contend for playoff berths.

“That’s the biggest goal, because all the other statistics and whatnot, you have no idea,” he said. “Obviously, I would love to win the Cy Young, but you could have a year where you threw really well — and there’s still a guy like Sandy. So I think for me, it’s just trying to stay healthy, get into a rhythm and continue that second half.”

Gallen may never have a six-start scoreless streak again. But a season full of seven-inning, one-run starts would be good enough to unseat his old teammate as the best pitcher in the league.

Logan Webb

As he stood by the Giants’ dugout at Scottsdale Stadium this month, watching the Giants’ pitchers take fielding practice, J.P. Ricciardi considered a question for about half a second. Does anyone in baseball have a better sinker than Logan Webb?

“Name me a better one,” Ricciardi said, rhetorically.

Framber Valdez, the Astros left-hander who won twice in the World Series last fall, is in the conversation. But for Ricciardi, a senior adviser for the Giants, the better comparison for Webb’s best pitch was the sinker of a Cy Young winner from his time as Toronto’s general manager: the Hall of Famer Roy Halladay.

That is high praise, but Webb, 26, has earned it. Only Valdez induced a higher percentage of ground balls in the majors last season (66.5 percent, to Webb’s 56.7), and Webb’s pitch is a marvel of movement.

“I caught his debut, and you could see in his demeanor and the way he went about it that he was going to be around for a long time,” said Stephen Vogt, Seattle’s bullpen coach, who played for the Giants in 2019. “But the way he’s moving that sinker now, it’s like a left-handed slider. It’s nasty.”

Webb, a right-hander, made eight starts in 2019, with a 5.22 E.R.A. That off-season, he resolved to improve in the popular style of the era: four-seam fastballs that stayed high through the strike zone, with an over-the-top delivery.

Then Webb got a call from Brian Bannister, the former major leaguer who had just joined the Giants as pitching director.

“We talked for like five minutes, trying to get to know each other, and he was like, ‘All right, I got something for you: We don’t want you to throw four-seamers anymore. We’re going to drop you down, and you’re going to try to throw like Chris Sale and Corey Kluber,’” Webb said. “And I’m just like, ‘What do you mean? I’m going to be all two-seams?’ It was confusing.”

Webb struggled again in 2020, but another off-season — and extra bullpen sessions while dealing with a shoulder issue the next June — helped Webb perfect the new arm angle. He went on to star in a 2021 division series loss to the Dodgers, allowing just one run in 14 ⅔ innings, and followed up that performance with a 2.90 E.R.A. across 32 starts last year.

Sinker specialists invite contact, because hitters usually bury the pitch into the ground for minimal damage. Those who throw it tend to be more efficient (Halladay was a seven-time league leader in complete games) and Webb said he hopes to pitch 200 innings, a threshold reached by only five pitchers last season. Three veterans from the 2019 Giants — Madison Bumgarner, Johnny Cueto and Jeff Samardzija — continue to inspire him.

“Being around those guys and learning from them really made me want to be that old-school type of pitcher where I can throw 200 innings every single year,” Webb said.

Webb uses plenty of sliders and changeups, too, but his sinker might put him ahead of his peers in an ever-evolving craft. The effectiveness and prevalence of high-spinning pitches, Webb believes, has been dulled since baseball started checking pitchers for foreign substances in mid-2021.

“Part of the craze about the four-seams and curveballs, there was a little bit of sticky stuff to that,” Webb said. “I’m not calling anybody out, I just think that was perfect for seeing the spin rate. With the sinkerball, I’m trying to see how low my spin can get, so maybe now that you obviously can’t do that anymore, guys are realizing that this kind of plays a little bit more.”

Webb averaged 7.6 strikeouts per nine innings last season, about the same rate as Greg Maddux in his mid-1990s prime. Another goal, Webb said, is “to throw a Maddux” — a complete-game shutout in fewer than 100 pitches, achieved only twice last season (by the Angels’ Patrick Sandoval and St. Louis’ Jordan Montgomery).

Webb already has a singular distinction in baseball history: He was the last full-time pitcher to hit a home run before both leagues enacted the designated hitter rule last season, seemingly for good. A .127 career hitter, he connected in the final game of the 2021 season.

“I miss hitting,” said Webb, a young pitcher with an old soul. “Hitting was fun. It made you feel like a kid again.”