A fastball up and off the plate to Guardians left-handed hitter Steven Kwan was an inauspicious beginning to Dodgers right-hander Roki Sasaki’s season debut.

The arm-side miss fell in line with a persistent spring-training pattern for Sasaki, who struggled with command from his first Cactus League start through his Freeway Series appearance last week.

Over the course of a seven-pitch strikeout, however, Sasaki adjusted — a skill that evaded him during the course of game action this spring.

In the Dodgers’ 4-2 loss Monday, Sasaki’s first start of the season was something of a best-case scenario. He held the Guardians to one run and four hits in four-plus innings. He issued two walks, the most notable difference from his spring struggles.

The Dodgers squandered the effort with a lack of offense, in their first loss of the season.

“We know he can do it here, and especially now that his velocity is back to closer to where it used to be,” Dodgers general manager Brandon Gomes said last week. “I feel like he puts us in a great position to win.”

Sasaki will have more to prove against stronger offenses than Cleveland’s. But his performance at least suggested that the Dodgers’ faith in him wasn’t misplaced.

“I think he’s in a good head space,” manager Dave Roberts said before the game. “Hopefully he can get past the whole spring and the inconsistency of the spring and get to pitching when games matter.”

The Dodgers kept pointing to the fact that they had seen Sasaki bounce back before.

“He could have cashed in last year,” Roberts said. “Given his health early, the lack of performance towards the middle of the year, towards the end he could have just written it off and started fresh in the offseason.

“But he was willing to pitch out of the bullpen, ramp back up and give us whatever we needed. So for me, that was something where he put himself out there. That’s why I have a lot of confidence right now (that he can) turn the corner from spring training.”

Sasaki had been working through shoulder discomfort a couple weeks before he landed on the injured list last May. In his eight starts before being sidelined, he posted a 4.72 earned-run average. His average fastball velocity plummeted from 98 mph in his MLB debut to 94.9 mph in his last start.

He returned from the injured list in time for two relief appearances in September, his fastball sitting above 99 mph, and a dominant postseason run. He didn’t allow a run in eight of his nine playoff outings, and he posted a 0.84 ERA.

“Without what Roki did in coming out of the ‘pen and being selfless,” Gomes said, “we probably don’t win the World Series last year.”

Sasaki still threw non-competitive pitches Monday. That inefficiency brought his pitch count up to 78 twice through the Guardians’ batting order, and Roberts pulled him when the lineup turned over again.

Sasaki also reigned in his misses, used both sides of the plate, and effectively deployed his new cutter as a putaway pitch early.

Through the first two innings, Sasaki held the Guardians scoreless, and to just one bloop single. But in the third, he threw a four-seam fastball down the middle to Austin Hedges and hung a cutter to Kwan for a pair of doubles and a run.

Next, Sasaki walked Chase DeLauter, and the inning threatened to spiral. But Sasaki locked in to strike out José Ramírez and induced Kyle Manzardo to line out, escaping without further damage.

With no outs and one runner on in the fifth inning, left-hander Tanner Scott took over. Dodgers fans sent Sasaki, who had been booed during his last spring start, off with a warm ovation.

After Scott, Dodgers left-hander Justin Wrobleski, in line to join the rotation when the schedule isn’t packed with off days, provided three innings. He gave up three runs.

The Dodgers didn’t score until the ninth inning, with the help of a little luck. Kyle Tucker reached base on a chopper that squeaked through the infield and then advanced all the way to third on a wild pitch. Mookie Betts drove him in with a line-drive double.

Betts later scored as Freddie Freeman grounded out to first.