ST. LOUIS — When the Dodgers re-signed Clayton Kershaw just as Spring Training started in February, they knew it would be months before they saw the left-hander, who underwent offseason left shoulder surgery, in Major League action.

At that time, the Dodgers were expecting Kershaw’s return to be a luxury and not a necessity. Coming into the season, the starting rotation was believed to be a strength for this year’s ballclub.

Instead, as the starting rotation deals with injuries and inconsistencies, the Dodgers are leaning on Kershaw to once again be the ace they desperately need. And as he has over the course of his illustrious career, the left-hander is delivering in a big way.

Kershaw’s best start since coming off the injured list came on Sunday, when he tossed six scoreless innings to lead the Dodgers to a 2-1 win over the Cardinals, helping Los Angeles wrap up the seven-game road trip with a winning record.

“I think that it’s not easy for a player to take on the responsibility of being a stopper, to go deep into a game, to manage stress a couple times and to keep going,” said Dodgers manager Dave Roberts. “You’ve got to be able to experience it, go through it, to be able to be that guy. And I think everyone wants to be that guy, but you’re not until you do it and you continue to do it. So that’s something Clayton’s done his entire career.”

Kershaw has done it in different ways throughout his 17 years in the bigs. At the beginning of his career, Kershaw had more velocity to lean on than he does now. Last season, Kershaw had to work through a left shoulder injury that was limiting what he could do on the field.

Now, after going through the first surgery of his career, Kershaw can focus solely on his pitching. Despite getting just four swings and misses on Sunday, Kershaw limited hard contact throughout his outing and made big pitches when he needed to. His efficiency was also off the charts, needing just 70 pitches to get through six innings.

“Honestly, I don’t even remember what it felt like to not have your shoulder hurt,” Kershaw said. “It’s nice. You wake up and everything feels good, shoulder feels good. It’s a good feeling.”

It’s an even better feeling for the Dodgers given the current state of the starting rotation. Los Angeles has struggled to get much production from its starters over the last few weeks.

Tyler Glasnow and Yoshinobu Yamamoto, the team’s two biggest offseason acquisitions, are both currently on the injured list. Glasnow is in his second IL stint, while Yamamoto has missed more than two months with a right shoulder injury.

Behind them, Bobby Miller has struggled in his sophomore season and Walker Buehler has also been in and out of the rotation as he’s battled his own inconsistencies following a second Tommy John surgery.

With all that happening, the Dodgers have needed someone to step up in a big way. It was strange for them to not have Kershaw around as much over the first few months of the season as he rehabbed his injury. But now that he’s back, he’s still the same Kershaw.

“He’s always been the stopper of the team,” said Dodgers catcher Austin Barnes. “His stuff was good. I thought he had a pretty good beat on them from the beginning. Even when he got in trouble, he kind of slowed it down a little bit and got us a big double play. I thought he was really, really good today.”

Behind Kershaw, the Dodgers’ offense, which was without Freddie Freeman as he nurses a jammed right middle finger, did just enough to help the left-hander secure his 212th career win.

Shohei Ohtani hit a solo homer in the fifth and Miguel Rojas tacked on with an RBI single of his own. Gavin Lux also continued his impressive second half with a three-hit game.

It was a win the Dodgers needed, and they got it from a familiar place.

“Every time I get to play defense behind Kersh, you’re playing defense behind a [potential] first-ballot Hall of Famer and one of the best competitors probably this sport has ever seen,” Lux said. “I didn’t get to do it last year, so every time I get to do it this year, it just means a little more.”