Still, he and the trainers had been concerned enough about Herzlich's health that they told him to see a doctor.
"I have good news and bad news," Sandy Herzlich said when McGovern called him back. "The good news is we've figured out what's wrong with Mark's back."
"OK, great. What's the bad news?"
Sandy Herzlich told him, and McGovern pulled over to the side of the road and parked his car, so he could steady himself before speaking again.
Bill McGovern is 50, and he wears a white goatee and has a voice that sounds like a bucket of gravel spilling onto the sidewalk. Before Chip Kelly hired him earlier this year to be the Eagles' linebackers coach, he had spent 27 years coaching college football, and never did he bond with a player as he did with Mark Herzlich.
"As a coach, you look at yourself as a teacher," McGovern said, "and there are those guys who come into the classroom who want to learn. Mark was one of those guys."
To Herzlich, McGovern became a counselor, a mentor, a confidant. When he broke up with a longtime girlfriend, when he was struggling with a class, when he just needed to bend someone's ear, Herzlich could always slip into McGovern's office, and McGovern would always listen. The two grew so close that even their families became friends.
"He really cares about his players as men," Herzlich said, "and that is sometimes tough to find in the football environment because everyone's looking at win-win-win."
But now McGovern was sitting in stunned silence in his car as Sandy Herzlich told him about Mark's diagnosis, a form of bone cancer called Ewing's sarcoma. He told McGovern that the doctors didn't know how dire the situation was, that Mark was alone in his room, processing the bad news. An hour passed before Mark called McGovern. "It's a bad deal," Mark said, "but I've dealt with it. I'm going to beat it."
From then on, coach and player developed a routine - a daily 20-minute phone conversation. Football was the only topic. McGovern would talk strategy and scheme and send Herzlich game films for feedback, and through chemotherapy, through round after round of radiation, through the insertion of a titanium rod into his left femur, Herzlich would review the film and offer critiques to his coach. It was a welcome respite, a chance to feel normal.
"I would call him, and I'd be saying, 'I've got to be ready to go. He might be down. Got to stay positive,' " McGovern said. "By the time I got off the phone, he had me fired up."
By September 2009, Herzlich was cancer-free. A year later, he returned to football, and when Boston College opened its 2010 season against Weber State, McGovern wriggled in front of the rest of the coaches and staff members on the BC sideline, telling them: "I want to see this. I want to see him come out of that tunnel."
"I use the word, and I don't want to slight the word, but it was," McGovern said. "It was inspirational."
Mark Herzlich wasn't drafted in the first round. He wasn't drafted at all. He signed as a free agent with the New York Giants in July 2011, and all he has done since then is play 34 games and win a Super Bowl with them, and he will suit up for them again Sunday, against the Eagles.
"My dad always says there were five people in the world who believed I could play football again," Herzlich said, "and Coach McGovern was one of them."
We hear a lot these days about the corruption of college sports, about the overreach of the NCAA and renegade programs and athletes who see enrolling in a university not as an opportunity for an education but as a necessary means to an uncertain end. So much of what we hear is true, too, and ugly.
But there's another side to that unseemliness, and the evidence for it will be at Lincoln Financial Field on Sunday. Bill McGovern's wife, Colleen, and their three daughters will be sitting in the stands next to Sandy; Mark's mother, Barb; and the rest of the Herzlich family, and Bill will be standing on the sideline, waiting to watch Mark come charging through another tunnel.
Afterward, they will find each other at midfield for a handshake and a hug, and as he looks at the kid who inspired him so much, the kid he considers a son, Bill McGovern may have to blink back tears, and steady himself one more time.