"I came home from practice and my parents said [Davis] was fired," said Mastromatteo, a 6-foot-1, 215-pound linebacker. "I was upset. A lot of things were going through my mind. I just had to calm down and view my options."
Two days after Davis's dismissal, Mastromatteo de-committed from UNC to help take a step back and revaluate the situation.
"[The UNC coaching staff] completely understood," Mastromatteo said. "They're great guys. They were completely understanding of where I was coming from.
"I needed to settle down and look at everything. I was just rethinking things. I wasn't really trying to do anything else [with another school]. I was just trying to calm down and look things over."
Mastromatteo received advice from Charlie Roman, Holy Spirit's head football coach.
"I give the same advice to all of our guys: chose the school for the school, not for the staff [and] not for the assistants," Roman said. "No matter where you go, you're not going to have the same assistant coach and there's a great chance you're not going to have the same head coach for the four or five years that you're there. So [I tell them] to pick a spot where you think the school is the right fit for you – not the coaching staff.
"I think Dan did a great job with that. North Carolina is just a beautiful, beautiful place with a tremendous academic reputation."
A week following his de-commitment, a composed Mastromatteo had a phone conversation with UNC's interim head coach Everett Withers, primary recruiter Allen Mogridge, and UNC's linebackers coach Art Kaufman.
"They still really, really wanted me and that made me really comfortable," Mastromatteo said. "They're trying hard to keep their jobs and I believe they'll do that."
After hanging up the phone, Mastromatteo discussed the situation with his parents. He then decided to call back Withers and re-commit.
"I decided that, either way, UNC was the place for me," Mastromatteo said. "I called Coach Withers back and said ‘I'm in. I really want to be a part of [UNC].'"
Since then, Mastromatteo has kept in constant communication with Mogridge. The two have also scheduled Mastromatteo's official visit to UNC for the weekend of Oct. 8 when the Tar Heels host Louisville. His parents will join him on trip, marking their first visit to Chapel Hill.
"That weekend just really worked out for my parents' schedule," Mastromatteo said. "I just really wanted them to see the place. They've heard how amazing it is."
With his recruitment finished – again – Mastromatteo's focus is helping Holy Spirit defend its NJSIAA Non-Public Group 3 State Title.
"We return the majority of our offensive starters and five guys on defense," Roman said. "So the expectations are extremely high right now. We expect to have a heck of a chance to repeat as state champions."
Mastromatteo starts at strong-side outside linebacker in Holy Spirit's 3-5 defense, where he often plays close to the line of scrimmage. On any given play, he will blitz or drop into coverage.
"He sets the edge for us and teams are forced to run the other way," Roman said. "It's like having a great corner in the NFL – if you have a great edge guy in high school, you can load up the other side and do some things schematically to really hurt people.
"He's a tremendous blitzer, has a non-stop motor, and [opponents] can't run to the outside to his side – he's just too strong for the opponents."
Roman believes all of Mastromatteo's football qualities will transfer to the collegiate level.
"He's a football kid that just loves the games," Roman said. "We've never had a kid with his talent level that plays as hard as he does. We've had some real good athletes over the years, but nobody has had as close to the motor that he has. That's what makes him special to us and special at the next level."
Mastromatteo will also start in Holy Spirit's "power run" offense this season.
"We like to play most of our guys just one way," Roman said. "But we're not in that situation this year. So he's going to have to play a lot of reps at fullback for us."