Sonny Gray of the A's walks to the dugout against...

Sonny Gray of the A's walks to the dugout against the Blue Jays at Rogers Centre on July 25, 2017, in Toronto. Credit: Getty Images / Tom Szczerbowski

The Yankees have their Game 1 starter for a playoff series that we’ll just assume is going to happen come October. And that’s clearly Luis Severino, who dominated the pathetic Reds for seven innings, striking out nine, in Wednesday’s 9-5 victory.

What should worry Joe Girardi, above anything else, is who gets the ball for Game 2. Ask us today, and the answer is CC Sabathia, as long as his legs don’t betray him over the next two months.

But the pitcher it should be is Sonny Gray, who at the moment still is a member of the A’s rotation. That needs to change, both to greatly improve the Yankees’ chances at winning the AL East and for them to make a serious postseason run.

The feeling here is that Gray will indeed wind up on the Yankees, only because general manager Brian Cashman has the pieces necessary to pull off such a deal and the fit is too perfect. A source confirmed Wednesday that the two teams continue to talk about a Gray trade, but added that “nothing was close” at game’s end.

The A’s want a top-rated centerfielder to be included in what is sure to be a multi-prospect package for Gray — who is under team control until 2020 — and the Yankees have at least two highly-regarded ones to choose from, either Jorge Mateo at Double-A Trenton or Estevan Florial at Low-A Charleston. The question then becomes whether Cashman is comfortable parting with Mateo or Florial only days after shipping Blake Rutherford, another coveted outfielder, to the White Sox for Todd Frazier, David Robertson and Tommy Kahnle.

Bending on Rutherford, the Yankees’ No. 3 prospect, was not insignificant. But Cashman realized that fortifying the bullpen was paramount based on the recent struggles of Aroldis Chapman, not to mention Dellin Betances. And now, with the Yankees having recovered from their June swoon, Cashman must treat the rotation with similar urgency.

It’s not like Cashman has to do an extreme makeover leading up to Monday’s non-waiver trade deadline. Thanks in large part to Severino, who improved to 2-0 with a 0.43 ERA over his last three starts, the Yankees have managed to hang with the AL’s best rotations during the past month. Before Wednesday, they were tied for second with the Astros in WHIP (1.26) and ranked fourth in both ERA (4.18) and opponent’s batting average (.249).

The teams ahead of them in these categories? The Red Sox, Rays, Indians and Astros. Even with Severino’s breakout season, Sabathia’s resurgence and the surprising maturity of rookie Jordan Montgomery, it’s unlikely the Yankees could stay on this course after losing Michael Pineda (Tommy John surgery) and instead leaning on Luis Cessa, Bryan Mitchell and Caleb Smith.

Homer-happy Masahiro Tanaka has been plagued by inconsistency. And what are the odds the rotation, as currently constructed, remains injury-free the rest of the way?

“That’s probably the one area that’s the hardest to relax with,” Girardi said. “I think that’s always a concern because of the health issue.”

Gray has battled plenty of physical bugaboos himself, but he appears to be rock-solid now. And after all that winter rebuilding discussion, the Yankees have chosen to again focus on the present rather than punt for 2018. There’s no more talk of ’17 being a bonus year. They don’t see much of a separation at the very top of the AL and adding someone like Gray — with the Yankees’ deep, powerful bullpen — could tip the scales. Over the past month, Gray has been one of the most effective starters in the game, with the fourth-best ERA (1.39) and sixth-best WHIP (0.84), a few ticks ahead of Chris Sale.

Gray definitely seems motivated to pitch his way out of dead-end Oakland. Cashman viewed the Yankees a lot differently last December when he passed on Sale without a fight. This time, if he really does intend to go for it, Cashman badly needs to secure a starter, and the sooner, the better. Gray is cheap, controllable and right there to be had, if the Yankees can agree on a price they can afford in terms of young talent.

No offense to CC, but getting that No. 2 needs to be their No. 1 priority.

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