September baseball prompts one to formulate visions … and then quickly scrap those visions and try again.

So when Luis Severino dominated the Blue Jays on Sunday afternoon at Yankee Stadium, picking up his first win of the season as the Yankees disposed of Toronto 8-3, he completed a vision transfusion of sorts that has taken place over the last week.

Imagining these guys as a reworking of last year’s Brewers is out. Wondering whether they can win with a more traditional pitching deployment? It’s back in like “Downton Abbey.”

“I feel 100 percent. I feel great,” Severino said, after throwing five shutout innings in his second start of 2019. “My pitches, every time they’re getting better and better.”

“You’ve got to be excited about what you saw again,” Aaron Boone said.

In the Yankees’ regular-season home finale, which they started with a lovely tribute to the retiring CC Sabathia, Severino expended 80 pitches as he allowed only three hits, walking none and striking out nine. For sure, you account for the fact that these Blue Jays departed The Bronx with a 63-93 record. Nevertheless, Severino’s fastball hit 99 mph and his slider appeared pretty darn good to the naked eye. He added 16 changeups, 11 of which went for strikes (thanks to Brooks Baseball’s PITCHf/x tool). Not bad for a guy who sat out from spring training through last week dealing with right shoulder and lat issues.

“I think we’re seeing enough from him as far as quality of stuff, command,” Boone said. “His next time out is going to be against Texas [on Saturday], and that’s a team that, if you’re making mistakes, they’re going to make you pay. I would say I’m very encouraged by what I continue to see.”

When the Yankees played at Detroit less than two weeks ago, a crusty Post columnist (OK, it was me) advocated that the Yankees should embrace the concept of “out-getters,” the term that Brewers manager Craig Counsell conceived last year as his guys nearly upended the Dodgers in the National League Championship Series. Milwaukee never pushed a starting pitcher as far as six innings in its 10 postseason games.

Since I wrote that on Sept. 10:

Dellin Betances, having just returned from season-long right shoulder and lat woes, tore his left Achilles tendon, sidelining him for the rest of the year.

Domingo German put himself on the restricted list with some apparently loathsome actions and will miss the playoffs thanks to his violation of baseball’s domestic violence rules.

Severino has thrown twice and totaled nine shutout frames.

Throw in James Paxton’s continued excellence and Masahiro Tanaka’s strong postseason history, and suddenly it makes sense for the Yankees to lean more heavily on their top three starters, all the more so with the team clearly (and intelligently) planning to deploy J.A. Happ as a second man in, pairing him with an opener who would likely be Chad Green.

Now, to be clear, the call for more from the top three does not beg for a repeat of Boone’s mistakes of last year, when he waited too long to lift Severino and Sabathia in the American League Division Series loss to the Red Sox. If they’re rolling and shoving, though? Don’t be as quick to get to the next out-getter, because the Yankees’ dirty dozen pitching corps is down to a terrific 10 (Zack Britton, Aroldis Chapman, Tommy Kahnle and Adam Ottavino in addition everyone else already mentioned) plus two or three more seat-fillers.

In an episode of “The Flash,” Leonard Snart (aka Captain Cold) offered advice: “Make the plan, execute the plan, expect the plan to go off the rails, throw away the plan.”

The Yankees’ first plan has started to go off the rails. It must be thrown away. Severino looks like someone ready to carry more of the load.

“I just need to go there and give five good innings or six good innings,” Severino said. That would be far more valuable than three or four good innings. It might even prove the difference in fulfilling visions of a parade.