PHILADELPHIA — Justin Verlander is set to make the start for the Astros on Thursday in Game 5 of the World Series, and even though it could be his last with Houston, the right-hander insisted that’s not on his mind.

“It’s premature,’’ Verlander said Wednesday, prior to the Astros’ 5-0 Game 4 win over the Phillies at Citizens Bank Park. “I try not to, really.”

He’s the only one, since even at 39, Verlander is set to be among the top free agents available this offseason and he could be a Yankee target for a second straight offseason.

Verlander is set to hit the open market, since he has a $25 million player option and figures to be able to get at least a one-year deal worth somewhere around $40 million — or even a longer deal — now that he’s come back successfully from Tommy John surgery.

He pitched just one game in 2020 and missed all of last season, but returned this year in top form, finishing with a league-leading 1.75 ERA and 0.829 WHIP in 175 innings over 28 starts with Houston.

He should now be in line for a deal worth an annual salary in the neighborhood of the $43.3 million per year Max Scherzer is making with the Mets.

The one red flag has been a pair of shaky outings in the postseason, including in Game 1 of the World Series against Philadelphia, when Verlander allowed five runs in five innings, blowing a five-run lead in the process.

But he also held the Yankees to one run over six innings in Game 1 of the ALCS, striking out 11.

The Yankees were interested in Verlander last year and offered him a one-year deal for $25 million, but Houston topped it with the second-year player option.

Verlander acknowledged the possible finality of Thursday’s outing in Philadelphia.

“Really and truly, it’s been a hell of a ride no matter what happens,’’ Verlander said. “Whether I stay or don’t, I’ve really enjoyed my time with this group of guys and the city and getting to know the city. And it’s really been a blessing and a wonderful time in my career.”

If Verlander does decide to test the open market, he’ll have plenty of options, in addition to the Yankees and Astros.

The Giants are another possible landing spot, especially with Carlos Rodon likely leaving as a free agent.

The Yankees have a solid rotation set for next season already, with Gerrit Cole at the top, Nestor Cortes and Frankie Montas back and likely Luis Severino, who has a $15 million team option, with Domingo German and Clarke Schmidt possible fifth starters or depth, with Jameson Taillon a free agent.

If the Yankees are looking to make a splash, they could look to Verlander.

“I’m trying not to think about it,’’ Verlander said of free agency. “I’m trying to be present. I mean, we talked a lot about how this year I’ve just tried to be more in the moment and be present and enjoy the ride and yeah, that will happen whenever it happens. We’ll see.”