Just when Mets’ fans thought it couldn’t get any worse, the Mets followed up a miserable road trip that ended with perhaps their worst loss of the season by stinking up Citi Field in a 2-1 loss to the Brewers on Monday night.

Even having Justin Verlander on the mound couldn’t fix what’s ailing the Mets, as they dropped their fifth in the last six games — and 16th of 21 — as the season that began with enormous expectations continues to spiral out of control.

They are now a season-worst eight games under .500 (35-43), a season-worst 16 games back of the NL East-leading Braves and 8 ½ games behind in the wild-card race.

“I don’t think anyone saw this coming,’’ Verlander said, seemingly stunned at what he’s become a part of.

On Monday, Verlander pitched five scoreless innings, but needed 100 pitches to get there and had to be replaced to start the sixth.

Drew Smith, fresh off a 10-game ban for violating the league’s sticky substance policy, entered with a one-run lead and gave up a two-run homer to Joey Wiemer to put Milwaukee ahead.

But as Buck Showalter said before the game, it’s impossible to point the finger at one area in which the team is lacking.

This time, the offense came up small against right-hander Colin Rea, scoring just one run — which was aided by an error by Milwaukee catcher William Contreras.

They finished with three hits on the night.

“We had a few balls that were blistered that went right at people,’’ Daniel Vogelbach said. “That’s how it’s going right now.”

Verlander was shaky throughout his outing.

He loaded the bases with one out in the first, but got out of it without allowing a run, as the Brewers squandered one of their many chances. They went 0-for-11 with runners in scoring position.

Verlander also gave up back-to-back hits with one out in the fourth, but with Luis Urias at second, Francisco Alvarez caught Blake Perkins off first base and picked him off for the second out and Wiemer popped to short to keep it scoreless.

Rea retired the first eight batters he faced before Brett Baty walked with two outs in the third.

The Mets didn’t get their first hit against Rea, who had allowed nine runs — eight earned — over 10 ¹/₃ innings in his previous two starts, until Starling Marte singled to start the bottom of the fourth.

Marte swiped second and went to third when Contreras’ throw went into center.

Wiemer, in center, threw wildly to third and Marte started for home, but smartly turned back.

He scored on Francisco Lindor’s sacrifice fly for the game’s first run.

And that was it.

“We’ve got to do a better job than three hits,’’ Showalter said. “We pitched pretty well. We’d like to take advantage of that.”

Verlander was replaced by Smith, who gave up a two-out, two-run homer to Wiemer to put the Mets in a 2-1 hole and the Mets were unable to get to three Milwaukee relievers.

They’ll have a tough task righting themselves Tuesday, when they will face Julio Teheran.

The right-hander who has resuscitated his career and has had considerable success against the Mets, with a 2.98 ERA over 29 games and a 2.40 career ERA in 14 starts at Citi Field.

“We’ve just got to keep trying,’’ Verlander said. “Hopefully it clicks for everybody. We’ve got to get going. Soon.”

“The game doesn’t care about your feelings,’’ Vogelbach said. “We’ve got to keep going and believe that one of these days — we don’t know when — it’s gonna turn. I think we do believe it’s gonna happen and a winning streak could start tomorrow.”

Asked how the Mets can be fixed, Showalter said, “Win. It’s not complicated. We’ve got to get back to how we’ve shown we can play, like we have in the past.”

But as Verlander pointed out, they’re running out of time.