So Harrison discovered Mayo in the cranny of the New England Patriots' locker room as he conducted an interview Friday morning.
"Excuse me, sir," Harrison said to the reporter. "Make sure you ask him about box call."
Mayo smiled sheepishly. He was busted.
Turns out that Mayo, an inside linebacker from Kecoughtan High and the Patriots' lone rookie starter, failed to hear a defensive check from Harrison, a Pro Bowl safety, during New England's victory over the New York Jets.
But "box call" is among Mayo's few missteps. And despite the hazing, Harrison is one of Mayo's most ardent boosters.
"One of the things you like about Jerod is he's a humble kid, a quiet guy," Harrison said. "He's willing to learn. A lot of guys drafted where he was come in and think they've got it all mapped out.
"Physically, the guy is big, he can run and he can hit. The mental aspect for any rookie is the hardest part. Every week, there are so many adjustments you have to make on the fly. Every team is so different."
Mayo, the 10th pick of April's draft following his junior season at the University of Tennessee, is adjusting well. He leads the team with 26 solo tackles and was the only Patriot to play every defensive snap the first two games.
"I don't really take a sense of pride in that," Mayo said. "I just try to go out there and do what's asked of me. I don't want to disappoint anybody. I'm not really a prideful person."
Good thing, too, because under coach Bill Belichick, individuals — even Tom Brady and his latest squeeze — are secondary.
That's why Mayo hoped to keep his interview hush-hush. Heaven help a lowly rookie were he deemed a self-promoter on a team with three Super Bowl championships this decade.
No worries there with Mayo, a chat with his hometown newspaper aside. His mother, Denise Hinds, and his grandparents taught him the value of modesty and hard work.
The five-year, $18.9-million contract Mayo signed? A new pickup truck is his only extravagance.
The wild nightlife of Boston? Mayo rents a house five minutes from the Patriots' stadium and more than a half-hour from the city.
"I'll go home for about an hour (after practice), relax and come right back," Mayo said. "Sometimes I'll be here until about 9 o'clock" watching game tape.
The 6-foot-1, 242-pound Mayo was first-team all-Southeastern Conference last season, and his 140 tackles were the most at Tennessee since 1990. He was the first linebacker drafted by the Patriots with their top pick since Southern California's Willie McGinest in 1994.
Belichick, player personnel guru Scott Pioli and defensive coordinator Dean Pees clearly had plans for Mayo. They released starting outside linebacker Rosevelt Colvin before the draft and moved Adalius Thomas from inside to outside, creating a spot for Mayo — if he was ready.
"He's been very consistent," Belichick said. "He's learning something every time he walks out onto the field, both in practice and in the games. I think he's shown … his speed, his range, toughness and his playmaking ability. …
"There are things that Jerod hasn't, that every rookie hasn't, seen before. Things that are a little bit different than the situation in practice. Things that we went through in practice, he learns from those, improves on them the next time and they're usually not problems. … He works awfully hard at it. He is a very attentive and detailed young man."
Mayo has the best set of teachers this side of the MIT faculty.
Six of his starting defensive teammates have earned Pro Bowl distinction, including fellow linebackers Mike Vrabel, Tedy Bruschi and Thomas. Every other defensive starter has at least four years' NFL experience — the total for the 10 is 85 seasons.
"I'm definitely living the dream; to go as high as I did to a winning organization is truly a blessing," Mayo said. "I'm just trying to learn each and every day from these older guys and just get better every week. You really can't ask for anything more. I'm just trying to be a sponge."
Bruschi, who plays the other inside-linebacker spot, has taken a particular interest in Mayo.
"He's really taken me under his wing and showed me what it means to be a professional," Mayo said. "Conducting yourself in an appropriate manner on and off the field. Taking care of your body, studying film, being a good citizen, things like that."
Mayo — his younger brothers play college football at Richmond and Hofstra — played outside linebacker his first two seasons at Tennessee before moving inside in 2007. Vols defensive coordinator John Chavis told Mayo his future was inside, and he was right.
Mayo said his tackling has been solid — he separated Baltimore rookie running back Ray Rice from his headgear during an exhibition game — but that he needs to improve his pass rush and pass coverage.
"It's the schemes," Mayo said of the college-to-pro transition, "and the thing about the NFL is, everybody's good. Especially when you're learning a new defense, it gets a little difficult because you're second-guessing yourself. As you continue to learn the playbook, you start to play faster.
"Just learning the playbook. The playbook is huge, it's huge."
New England is 3-2 entering Monday's home game against the 4-2 Denver Broncos and bears no resemblance to last season's juggernaut. Brady is out for the season with a knee injury and the offense scores 50 percent fewer points, placing a greater burden on the defense.
The Patriots yielded 68 points combined in losses to Miami and San Diego. Chargers quarterback Philip Rivers completed passes of 48, 49 and 59 yards.
"We just have to get better, each and every one of us," Mayo said.
Mayo peered around a corner of the locker room, still keeping watch for potential tormentors. He was hungry, and practice started in about an hour.
Time for lunch and a closing thought.
"I used to play with these guys on Madden (video games)," Mayo said. "To come out and be playing against Brett Favre and LaDainian Tomlinson and guys like that? It's just amazing."