PHILADELPHIA -- The circumstances couldn’t have lined up any better for Mason Black.

A native of Scranton, Pa., Black will get a chance to make his Major League debut against his childhood team when he’s called up to start for the Giants in Monday’s series finale at Citizens Bank Park.

Black, who is ranked as the club’s No. 7 prospect by MLB Pipeline, will fill the rotation opening left by the injury to left-hander Blake Snell, who is currently on the 15-day injured list with a left adductor strain.

“It’s kind of storybook,” Black said on Sunday. “Being so close to home, hopefully having a chance to have a lot of people come up and see. It’s really exciting.”

Black, a third-round pick (No. 85 overall) out of Lehigh University in the 2021 MLB Draft, had been viewed as a strong candidate to earn a spot in the Opening Day rotation this spring. But he ended up being one of the Giants’ final cuts after they opted to carry Snell on their initial 26-man roster.

The 24-year-old right-hander continued to make his case for a promotion once he reported to Triple-A Sacramento, though, logging a Pacific Coast League-best 1.01 ERA with 29 strikeouts over 26 2/3 innings through his first six starts for the River Cats. Black, who pairs a mid-to-upper 90s sinker with a wipeout slider, was especially dominant over his past four outings, allowing only one unearned run over 18 innings.

“He definitely deserves it based on what he’s done at Triple-A,” Giants manager Bob Melvin said. “To be able to come here and get his first start -- it’s not the easiest opponent in the world -- but I think he’s just got to insulate on, ‘I’m a big leaguer now,’ and go out there and do his thing and stay with his strengths.

“He’s been pitching pretty well. Tomorrow will be a very, very special day for him.”

Black said he arrived in Philadelphia on Saturday night, giving him a chance to cheer on his girlfriend, Bridget, in Sunday morning’s Broad Street Run, an annual 10-mile race through the heart of the city. The roles will be reversed on Monday, when Black is expected to have plenty of loved ones, including his parents, George and Tara, in the ballpark for his first career start.

“My mom was definitely emotional,” Black said. “My dad couldn’t believe it. It was just everyone trying to manage their emotions here.”

Black grew up a huge Phillies fan and said he still remembers sitting behind Pat Burrell -- now a hitting coach with the Giants -- in the right-field bleachers when he attended his first game at Citizens Bank Park.

“There are good memories here,” Black said, smiling.

Black wasn’t the only new arrival in the Giants’ clubhouse on Sunday. After placing Tom Murphy on the 10-day injured list with a left knee sprain, San Francisco also called up Black’s batterymate, Jakson Reetz, from Triple-A, giving the 28-year-old backstop an opportunity to return to the Majors for the first time since 2021.

“He’s been doing really well this year,” Reetz said of Black. “I’m super excited for his future. He’s really come a long way since last year. I think everyone’s going to be very surprised at how well he’s doing.”

With Patrick Bailey (concussion symptoms) and Murphy both injured, the Giants are expected to lean on Blake Sabol and Reetz to fill in behind the plate for the time being.

“We had Jakson in [big league camp] in the spring, and we saw enough from him to know that we’re confident in him behind the plate,” Melvin said. “First and foremost with a guy like him, it’s about catching the staff, receiving and defense. I think offense is probably secondary in that role right now. But both these guys have been around our pitching staff, so at least we have that.”

Black isn’t on the 40-man roster, so the Giants will have to make room for him on Monday. Right-hander Mitch White was designated for assignment on Sunday to open up a spot for Reetz, though San Francisco could consider transferring Murphy to the 60-day IL if he’s expected to miss significant time with the knee injury.

The Giants are still reviewing the results of Murphy’s MRI exam, though the 33-year-old veteran had his left knee in a brace and was limping around the clubhouse on Sunday.