"When he came in, you could tell the kid was special by not just his efforts on the football field," said Callahan of Harmon, who is known as DJ to his friends and family. "And to be honest with you, to get to know Derek, you need to understand his mom and the relationship that he had with her, what a special lady she was, having the situation with her surgeries and everything else going on. There wasn't a thing that she missed regarding Derek. I think she spent more time in my office than some of my assistant coaches, not just checking up on him, but wanting to know how he was doing, what we could do to make them better, and not just on the football field, but in the classroom.
"I mean, I think she knew the name of his girlfriends I think before he knew it. She was definitely on top of it. And again, just an extremely special woman. He loved her to death. For a kid that age to show the emotion that he did with her and not be embarrassed, most kids are kind of like, 'Ma, get away, get away.'
But she would be right in there with him. And he was totally accepting. So that part of them, you would never, never think that that would be the same guy you see on Saturday afternoon, or, for me, Friday night playing football. She was, like I said, just a special person."
Harmon became an immediate starter for the Bulldogs as a freshman - on the offensive line. In his sophomore year, he began playing on the defensive line, as well.
Even though Loyola is a tiny school, playing in Michigan's smallest classification, the Bulldogs played a schedule that included much larger schools. They didn't back down from anyone, and neither did Harmon.
"Loyola is a small Jesuit boys school. We played the biggest schools," Callahan said. "We played anybody, and he went and played the biggest school, Division one, two, it didn't matter, and pretty much beat them all. But, you know, obviously he was a large part of it, so his competition wasn't at a lower level, or where people may think. We played the best in the state, and he went up against the best even as a freshman and sophomore. He never backed down. He was always taking care of business."
Just like his mother taught him.
Then again, because of his size, Harmon grew up playing against older competition. A large child, Harmon was always forced to play one or even two years above his age level when he began playing football at the age of 5 because he was so much bigger than his peers.
Kevin Rogers was the head coach at Loyola in Harmon's senior season. But he had seen the youngster while watching youth football games in the area.
Harmon stood out in a crowd, even then.
"He was always bigger than most, definitely, playing youth football," said Rogers. "You kind of had an eye on them, watching him play growing up. So, I definitely knew about him. I didn't really have that type of relationship that I have now with him, but definitely I saw him playing and kind of saw him grow and then develop."
Thing was, Harmon was a big kid. But he also was carrying extra weight.
"When he came in, he had a little, little fat he had to get rid of, but obviously he started working on it and took care of that part," Callahan said.