The pangs of guilt would eventually hit him. It’s just where it would penetrate William Foster III’s conscience and seep into his subconscious. Everyone would sometimes be forced to back away from Foster in his grade school lunch line, because out of the blue, he would shadow box if he missed a day at the gym.

Foster wouldn’t even know he was doing it.

It showed how deeply entrenched the sport was in his life.

On Friday night, Foster III will make his TV debut on Showtime’s ShoBox: The New Generation from the Caribe Royale Resort (9 p.m. ET/PT) in Orlando, Florida.

Foster (13-0, 9 knockouts) will be taking on Edwin De Los Santos (13-0, 12 KOs) in an eight-round, junior lightweight bout in support of the main event between Luis Nunez (15-0, 11 KOs) against Carlos Arrieta (14-0, 8 KOs) in a 10-round lightweight bout.

Starling Castillo (16-0, 12 KOs) will take on Otar Eranosyan (10-0, 6 KOs) in an eight-round fight at lightweight.

Foster, 28, comes from a boxing family. His father began training William when he was four years old and his older brother, Charles, is an undefeated light heavyweight.

“Boxing is a part of me, it’s a big part of my life,” William said. “I would watch the big fights with my father growing up. I would watch Prince Naseem Hamed and Floyd Mayweather Jr. growing up. My dad would come back from the gym and he would teach us what he learned that day.

“You can say my living room was like a baby boxing gym. But as I got older, there were some distractions. I never really lost a week at the gym but there were times I would miss a day doing normal kid things. I wanted to spend time with my friends and go out with girls.

“But you get to the point where you miss a day or a certain time, I would throw punches waiting in the lunch line, and my friends would all say, ‘What the hell are you doing?’ and I didn’t even know I was doing it.”

De Los Santos, a 22-year-old southpaw, is looking for his eighth-straight knockout. Foster has won three of his last four bouts by KO. Four of De Los Santos’ last six opponents did not get out of the first round.

The “Silent Assassin” says he’s ready for anything De Los Santos brings. In February 2021, Foster came to Philadelphia and won a six-round decision over previously undefeated Donald Smith. In April 2018, Foster handed another undefeated prospect his first loss, when he won an eight-round decision over Sulaiman Segawa.

“I’m excited about this,” William said. “This is my introduction and my message to everyone at 130. I want to make a good impression and let everyone know who I am. He’s a southpaw and I’ve faced three southpaws. This is nothing new for me.”

Foster assures that the inner version of him, the teenager who was once throwing punches in the lunch line, will be there Friday night.

Joseph Santoliquito is an award-winning sportswriter who has been working for Ring Magazine/RingTV.com since October 1997 and is the president of the Boxing Writers Association of America. He can be followed on twitter @JSantoliquito.

READ THE MARCH ISSUE OF THE RING FOR FREE VIA THE NEW APP NOW. SUBSCRIBE NOW TO ACCESS MORE THAN 10 YEARS OF BACK ISSUES.