If the Mets are finally going to get their season together, now would be the time to do it.

Justin Verlander was as sharp as he has been all season and the Mets used a four-run fourth inning to win their third straight game, a 5-1 victory over the White Sox at Citi Field on Wednesday night.

With the clock ticking down toward the Aug. 1 trade deadline, the Mets still don’t look like much of a threat, but they still believe that can change.

For that to happen, Verlander and company will have to deliver a lot more performances like the one they did Wednesday — and soon.

“We’ve been fighting and clawing and doing everything we can,’’ said Verlander, who allowed one run over eight innings, using an improved slider.

“We see the leaderboard,” the right-hander said. “We understand where we’re at. We need to go on a run. Hopefully this is the beginning of something special.”

This has happened before, most recently during a six-game winning streak before the All-Star break, but the Mets haven’t been able to sustain it.

They’ll go for the series sweep against Chicago on Thursday and could be provided with another reason for optimism: Jose Quintana is set to make his debut for the Mets after coming back from a fractured rib that set him back in spring training.

With less than two weeks to go before the trade deadline, the Mets have to decide whether to buy or sell.

“You never want to wait around,’’ Verlander said of the urgency to get back in the playoff race. “You get in a hole and you’ve got to dig yourself out. We have not quite done that yet. We know when the trade deadline is. No one has given any indication of what we’re gonna do.”

Verlander, coming off a messy, six-walk performance last Friday in a loss to the Dodgers that nevertheless left him encouraged because he only gave up a pair of hits, was at his best on Wednesday.

He started off strong, getting ahead 0-2 to each batter in a first inning in which he retired the side in order, with 13 of his 14 pitches strikes.

The right-hander whiffed three of the first four batters he faced, retired the first nine and didn’t allow a baserunner until Andrew Benintendi’s single to center to start the fourth.

After the hit by Benintendi, Verlander retired 10 in a row — and had a five-pitch sixth inning — before Luis Robert Jr. got the White Sox on the board with a 405-foot solo homer to left-center with one out in the seventh.

Brett Baty got the Mets’ offense going by leading off the bottom of the inning with a home run to center for a 1-0 lead. It was his seventh homer of the year and his second in as many games.

Francisco Alvarez, who homered twice on Tuesday, drove in Pete Alonso with a single through the right side of the infield in the fourth.

Alonso had walked to start the rally and Jeff McNeil was then drilled by a pitch.

After Alvarez’s hit, Daniel Vogelbach walked to load the bases for Baty, whose groundout scored McNeil before Luis Guillorme’s sacrifice fly made it 4-0.

Brandon Nimmo, hitless in his previous 11 at-bats, then drilled a double that scored Baty from first to make it a four-run inning.

After Robert’s homer in the seventh, Verlander pitched out of his first trouble of the night. He walked Jake Burger and after Yasmani Grandal popped out, Gavin Sheets reached on an infield hit. Following a visit from pitching coach Jeremy Hefner, Verlander struck out Carlos Perez to end the inning.

Verlander ended up allowing just three hits and a walk in the 100-pitch performance, with the eight innings matching his season-high.

“We can go on a stretch where we play the way we know we can play,’’ Verlander said. “We haven’t done it yet. You’ve seen flashes of it at times, but we haven’t really put it together.”