In series losses to the San Diego Padres and Washington Nationals at the start of a nine-game homestand, the Dodgers’ struggles had followed a few recurring themes.

Their starting pitching wasn’t great. Their bullpen repeatedly stubbed its toe. And their top-heavy lineup teetered with everyone from Chris Taylor to Freddie Freeman scuffling to start the season.

If all that wasn’t enough, the Dodgers added another problem to the mix Friday night.

In a 9-4 loss to the New York Mets to open a three-game weekend series, the Dodgers’ already shaky defense committed several more costly errors, emerging as the latest problem to address in what has become a 2-5 skid at Chavez Ravine.

“Overall, not a whole lot of positives, to be quite honest,” manager Dave Roberts said. “All facets of the game, we didn’t perform.”

Friday could have been a day for the Dodgers (12-10) to take a step forward.

Yoshinobu Yamamoto grinded through the longest start of his rookie season, completing six stressful innings despite giving up four runs (one was unearned, thanks to some defensive miscues in the second) and seven hits.

The Dodgers briefly erased an early four-run deficit, mounting the kind of midgame rally that has been rare since the opening weeks of the season.

Taylor even got a key hit, ending his one-for-35 start (including an 0-for-30 mark entering Friday) by tying the score with a two-run single in the sixth.

It wasn’t enough — not on a night the Dodgers squandered other prime scoring opportunities, once again struggled to find production from the bullpen, and most consequentially were hurt by several misplays in the field.

“I think there’s certainly frustration,” Roberts said of his team’s recent slide. “I know we’re a talented team and we’re certainly capable of playing a complete baseball game in all facets.

So I think that we’re going to have to get back to work, which our guys do a great job of, and go out there and do it. But certainly frustrating. Losing doesn’t feel good.”

The Dodgers’ shoddy defense started in the second inning.

After DJ Stewart opened the scoring with a solo home run off Yamamoto, Francisco Alvarez reached second on a throwing error by catcher Will Smith, who airmailed an underhand toss to first on a dribbler in front of the plate.

Smith then failed to corral a potential inning-ending third strike on a foul tip, allowing Harrison Bader to score Alvarez with a single to center — an RBI aided by Andy Pages’ bobbling of the ball in the outfield, negating any attempt for a play at the plate.

“Things like that seem to always get you,” Roberts said. “That’s kind of what’s happening right now.”

The Mets stretched their lead to 4-0 in the third, before Yamamoto finally settled down (he racked up a season-high nine strikeouts while pitching into the sixth inning for the first time in MLB) and the Dodgers’ scuffling offense found some life.

Teoscar Hernández hit an RBI single in the fourth inning, raising his batting average with runners in scoring position this season to .333.

Shohei Ohtani, who scored the Dodgers’ first run after stealing second base, knocked in another run in the fifth, delivering in a situational at-bat after starting the season one for 19 with runners in scoring position.

Taylor even came through in the clutch, roping a two-run single to left with the bases loaded in the sixth inning to tie the score at 4-4.

“Just felt good to do something to help the team, honestly,” said Taylor, who has attributed his opening-month struggles to a failed offseason swing change.

“It’s no secret I’ve been grinding a little bit.”

But then, just as the Dodgers had climbed back into the game, a combination of bad defense and relief pitching allowed the Mets (11-8) to take control again.

With one out in the seventh, Mookie Betts suffered his third error of the season at shortstop by spiking a routine throw to first.

In the next at-bat, Francisco Lindor took right-hander Daniel Hudson deep, launching a two-run blast that put the Mets back in front.

The Dodgers’ bullpen kept digging a bigger hole from there. Joe Kelly gave up two runs in the eighth, raising his ERA to 7.27. Ryan Brasier was tagged with an insurance run in the ninth, raising his ERA to 5.00 in a continued regression from last year.

Amid all those mounting issues, the last thing the Dodgers needed was for their defensive concerns to resurface.

Instead, on a rare night owner Mark Walter was in attendance, the team’s recent struggles only worsened — further highlighting flaws that even Walter’s $1.4 billion of spending this offseason have thus far failed to prevent.

“That was just not a good game,” said Freeman, who went hitless in five at-bats to extend a three-for-27 slump on this homestand.

“It’s April, we’re gonna go through the ups and downs. … But if we just play better baseball, we’re going to win. Our team is way too good. I think we all know that.”