OAKLAND, Calif. — Greg Weissert hasn’t made his debut with the Yankees, but the right-hander already knows how to pitch in The Bronx. 

The right-hander, who pitched at Fordham University, was set to be called up from Triple-A Scranton/Wilkes-Barre on Thursday to replace the injured Nestor Cortes on the roster. He will be part of a bullpen that’s missing Scott Effross (shoulder), Albert Abreu (elbow) and Clay Holmes (back), with Aroldis Chapman unable to be used in important spots and Zack Britton having just begun a rehab assignment from UCL surgery. 

Weissert has thrived with SWB this season, with 67 strikeouts in 46 innings, as well as a WHIP of 0.891 in 40 appearances. 

Weissert pitched three years at Fordham before being drafted by the Yankees in the 18th round in 2016. 

The 27-year-old, who also played at Bay Shore High School on Long Island, will be the first Fordham player to play for the Yankees since Johnny Murphy in 1946. 

Murphy, who was also a right-handed reliever, spent almost all of his 13-year career in The Bronx and was part of seven World Series-winning teams and later was general manager of the Mets when they won the 1969 World Series. Hank Borowy spent parts of four seasons with the Yankees as a reliever from 1942-45. 

Weissert’s coach at Fordham, Kevin Leighton, knows if nothing else, his former player has the mindset to succeed with the Yankees. 

“He’s kind of a bulldog,’’ Leighton said by phone before heading to Oakland for Weissert’s debut. “He’s a tough kid with a no-fear type of mentality. He always wanted the ball.” 

Leighton said he used Weissert as a closer as a freshman before moving him to the rotation as a sophomore and junior. 

“What makes him good is he always pitched with a little bit of ego to him,’’ said Leighton, a former Seton Hall catcher. “He knows he’s pretty good and I think he pitches that way.” 

Weissert has been especially impressive lately, with one earned run allowed in his last 29 ¹/₃ innings, while striking out 44 and walking seven. And he has 18 saves. 

“You could see he was never afraid,’’ Leighton said. “He pitches with attitude and aggressiveness. He wasn’t a showboat type of guy, but you knew when he was on the mound, he was confident. Whether he did well or struggled, he believed in his stuff and gave everything he had. That’s what I want from someone on the mound and what makes him good. I don’t know how he’ll react in pinstripes, but he won’t be afraid of the big moment.” 

Holmes will throw a bullpen session Friday. 

So far, in the deal that brought Frankie Montas to the Yankees, the best pitcher involved in the trade has been JP Sears. 

The Yankees will get their first look from an opposing point of view of the lefty when he starts against them for the A’s on Friday night. 

While Montas has quieted some fears he was going to be a new version of Sonny Gray — who flamed out with the Yankees after starring with the A’s in pitching-friendly Oakland — Sears has been excellent with his new team, much like he was with the Yankees earlier this season. 

In three games, all starts, Sears has allowed just three runs in 15 ¹/₃ innings for a 1.76 ERA. 

He hasn’t been as unhittable with Oakland as he was in The Bronx, with a WHIP of 1.109 with the A’s, as opposed to the other-wordly 0.864 as a Yankee, but he’s been just as effective. 

The 26-year-old lefty went to Oakland, along with other minor league pitching prospects Ken Waldichuk and Luis Medina, as well as minor league infielder Cooper Bowman, in exchange for Montas and Lou Trivino.