Carlos Mendoza insists he’s not concerned. But the trend, at this point, has become a concerning one.

This isn’t the version of Kodai Senga that the Mets envisioned anchoring their rotation. That, partially, made them comfortable with not acquiring a starter at the trade deadline.

That he can deliver ace-esque outings — the ones blending length with results — over and over again.

The Mets have other rotation questions to answer, but Senga’s trajectory since returning last month has joined that list.

He allowed four runs on five hits, walked three batters and exited after just four innings and 71 pitches during the 12-6 win over the Giants on Saturday at Citi Field. He has topped 77 pitches just once since returning from a hamstring strain in July. He has allowed three or more runs in three consecutive starts, while issuing eight walks across those 12 innings.

“I’m not worried about him,” Mendoza said. “We’re not worried. But I’m pretty sure he’s frustrated because he wants to go deep in games and he wants to perform. And he will.”

Senga and Mendoza both said he’s healthy, while Senga added his issue Saturday revolved around pitches that weren’t competitive. He struggled to hit the strike zone, fell behind in counts and has “just gotta stay on the attack,” Mendoza said.

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David Stearns’ decision to not add a starter at the deadline only injected extra significance to each start from Senga, too.

Clay Holmes collected a 4.90 across six July starts and has logged 117 ¹/₃ innings, nearly double his previous career high. Only David Peterson has provided any depth during outings, too. If the Mets opt to bring up top prospects, there could be growing pains.

So the Mets, more than anything, need Senga to serve as their constant.

But he allowed at least two base runners in each of his innings Saturday, and ex-Met Dominic Smith launched a homer to right in the third inning to erase an early Mets lead.

Senga loaded the bases with no outs the previous inning, too, after allowing a double, hitting a batter and issuing a walk, but a double play helped limit the damage to just a run.

“They weren’t good,” Senga said of the runs through a team interpreter. “It wasn’t a pretty sight to see, and as the one actually giving them up, it obviously didn’t feel good, either. So moving forward I hope to be able to stay in the game and perform at the level that the team would want for me to stay in the game.”

For one game, the Mets offense erupted for more than enough production to help mask Senga’s early struggles. The bullpen covered the extra innings. But at some point, they’ll need Senga to deliver his vintage performances. To help carry the rotation again.

To fix what he hasn’t been able to recently.

“Mechanically, I may be overcompensating in certain areas, just not all the way back yet maybe,” Senga said. “But again, trying to get back to my best performance as quickly as possible.”