In another universe, on another roster, news of Carlos Carrasco’s extended rehab from a torn right hamstring might have driven the Mets to misery. When the Mets acquired Carrasco from Cleveland this winter, they envisioned him serving as the No. 2 in their rotation behind Jacob deGrom. Having him miss the first two months of the season was not their ideal plan.

Fortunately the Mets acquired Taijuan Walker at the dawn of Spring Training for just this sort of problem. They wanted Walker to provide rotation depth and back-end stability. They believed he could help.

They just might not have realized quite how much.

Walker dominated throughout a 4-1 win over the Cardinals on Thursday, delivering seven near-perfect innings to help the Mets earn a four-game series split in St. Louis. The right-hander allowed just one hit -- a Nolan Arenado shift-beater to lead off the second inning -- and one unearned run following a Jonathan Villar error. He was otherwise untouchable, retiring a career-best 18 consecutive batters from the second through seventh innings.

“For me, he’s a guy you can’t sleep on,” Mets catcher James McCann said. “He should be in the talks of being that guy at the top of the rotation the way he’s throwing the ball, the stuff that he has. I think it just shows the depth that we have in the rotation. The type of quality arms that we have, it’s a special thing for sure.”

The effort lowered Walker’s ERA to 2.38, which speaks of his consistency throughout the early season. And yet not all of his outings have been equal. Across his first three, Walker averaged fewer than five innings per start and walked 18 percent of the batters he faced. Since then, he’s averaged nearly seven innings per game and issued free passes to just 5 percent of opposing hitters -- including zero at Busch Stadium.

“He was pretty much throwing it where he wanted to,” Cardinals manager Mike Shildt said. “He was in control of what he was doing. He was able to keep a really good lineup to one run.”

Throwing strikes has always been the goal for Walker, who understands that his five-pitch mix can be difficult even for lineups featuring Arenado, Paul Goldschmidt and other perennial All-Stars. Walker’s pure stuff has proven better than ever in his first season with the Mets; now more than three years removed from Tommy John surgery, he’s seen each of his pitches spike in velocity. In particular, Walker’s average four-seamer has increased more than a full mile per hour since last season, from 93.2 to 94.3. He topped out at 96.6 mph against the Cardinals, catching Goldschmidt looking on another 96 mph heater in the first.

“It’s been a little more than what we expected,” manager Luis Rojas said. “He’s throwing harder than what he was last year, so that’s making the secondary stuff play better now. He’s thrown the ball so good.”

The problem has been keeping the ball in the zone on a regular basis. To that end, Walker has worked tirelessly on his mechanics in his bullpen sessions, or while playing catch, or even in front of hotel-room mirrors. He believes by doing so, he has cleaned up some of the early inconsistencies that prevented him from locating the baseball more consistently.

“I felt like I could throw everything for strikes when I needed to,” Walker said, “even when I got behind.”

Of all teams, the Cardinals understand how difficult that can be, considering their pitchers walked 11 batters -- including three with the bases loaded -- to hand a scuffling offense some life. Dominic Smith added an RBI hit and Francisco Lindor reached base four times, singling in the ninth to snap an 0-for-26 skid at the plate. It was more than enough for Walker, Trevor May and Edwin Díaz, who would have combined on a shutout if not for Villar’s error.

Such has been the case throughout the early season for the Mets, who have consistently ranked among the best-pitching and worst-hitting teams in the Majors. Walker has played a significant role in that disparity, even as deGrom and Marcus Stroman have overshadowed some of his early success. Combined, those three pitchers have allowed the Mets to fret less about Carrasco, whose absence will linger for at least another three to four weeks.

To be certain: the Mets want Carrasco back as soon as possible. It’s just that deGrom, Stroman and Walker have helped make his absence significantly more tenable.

“They’re all right,” Lindor deadpanned when asked about the rotation. “Naw, they’re really good, man. They’re fun to watch. They throw strikes. They attack. They all pitch a little different, but it seems like they all have a great approach.”