LOS ANGELES — The ball sailed into the air and Clayton Kershaw rested his hands on his knees, head down, legs slightly bent, back toward home plate, a painful, all-too-familiar sight in this place, at this time of year. Gabriel Moreno had belted the three-run homer that gave the Arizona Diamondbacks a five-run lead before Kershaw recorded the first out in Game 1 of the National League Division Series on Saturday night, delivering the decisive blow within the first 10 minutes.

The Los Angeles Dodgers, their starting rotation in flux heading into October, have never needed Kershaw more. But they have never been more uncertain about what he can provide for them. Their playoff opener provided an ominous sign: six runs allowed, one out recorded and quite possibly the worst postseason start in baseball history.

“Disappointing,” Kershaw said after an 11-2 loss. “Embarrassing. You just feel like you let everybody down. The guys, a whole organization, that looked to you to pitch well in Game 1. It’s just embarrassing, really. So I just feel like I let everybody down. It’s a tough way to start the postseason. Obviously, we still have a chance at this thing, but that wasn’t the way it should’ve started for me.”

The final two months of the regular season saw Kershaw pitch brilliantly through a tender left shoulder. His fastball was a tick or two slower, his outings came after an additional day or two of rest, but he pitched to a 2.23 ERA in an eight-start stretch and was kept to only about five innings at a time in an effort to keep his arm fresh for the games that mattered most.

Game 1 began with Dodgers manager Dave Roberts noting that “this is as good as he’s felt physically in the last couple months.” It ended with Kershaw becoming the first playoff pitcher in major league history to allow five hits and five runs before recording an out. With Kershaw failing to finish the first inning for the first time in 454 career starts. With Kershaw and his famously checkered postseason track record joining only three others in allowing six-plus runs while recording one out or fewer in postseason history.

Dodgers catcher Will Smith said Kershaw’s stuff “looked like the normal stuff that it’s been all year.” Roberts said there was nothing physically wrong, a point Kershaw echoed.

“I feel fine,” Kershaw said when asked if he feels healthy enough to help the team moving forward. “I feel fine. I just didn’t make enough good pitches, obviously, tonight. There’s nothing health-related here; just bad pitching.”

Kershaw’s second pitch, a 73-mph curveball slightly low, was lined 116 mph to center field and bounced off the heel of James Outman‘s glove, a double that probably should have been ruled an error. Outman, a rookie, said the ball sped up on him but also that his “nerves kind of got the best of me.”

Corbin Carroll and Tommy Pham followed with back-to-back singles, Christian Walker added a double, and then Moreno, whose status was uncertain after he was hit in the head by a backswing during Arizona’s last game Wednesday, blasted a 419-foot home run to left-center field, leaving a still-arriving Dodger Stadium crowd in stunned silence.

Three batters later, after a one-out walk and another double, Kershaw exited, making way for rookie right-hander Emmet Sheehan.

“Usually Clayton does a great job of controlling, managing damage,” Roberts said. “And tonight unfortunately we didn’t do that.”

The outing increased Kershaw’s postseason ERA from 4.22 to 4.49 in 194⅓ innings. It’s two runs higher than his sterling regular-season ERA of 2.48 and stands as the highest among the 31 pitchers throughout major league history with more than 100 innings in the playoffs.

The differential has proved to be a major stain on Kershaw’s reputation, but it is also complicated, burdened by several outings in which he pitched on short rest, was used in relief or was kept in longer than normal. This time, it jumped significantly at a time when Kershaw — 35 years old, with nearly 3,000 innings under his belt and an assortment of injuries in his track record — is not fully healthy.

“I don’t think anybody in the baseball world was expecting that,” said Dodgers first baseman Freddie Freeman, part of an offense that did little against an aggressive Merrill Kelly. “But next time Clayton Kershaw’s on the mound, we’ll be just as confident again. Hopefully we can get him back on that mound.”

Kershaw’s next start, Roberts said, is still lined up for Game 4 at Chase Field in Phoenix on Thursday, an outing that will take place unless the Dodgers are swept.

Kershaw is the only man still standing from the Dodgers’ initial rotation. Dustin May and Tony Gonsolin underwent season-ending surgeries; Julio Urias is on administrative leave after allegations of domestic violence; Noah Syndergaard struggled mightily before being traded away; and Walker Buehler didn’t make it back from his second Tommy John surgery in time to help.

The Dodgers’ postseason pitching plan consists of a lot of rookies, a lot of relievers and a lot of unconventionality. But if they hope to make another deep run, and avoid the early-round disappointments that have plagued them in recent years, they need Kershaw to tap back into some of what has made him great.

They need him to recover dramatically for Game 4.

“I’ll be ready,” Kershaw said. “Yeah, I’ll be ready.”