John Harbaugh? He played defensive back in college, but no further. By all accounts, for 24 seasons Harbaugh has been a good lieutenant -- smart, detail-oriented and loyal to a fault.
"They would have been crazy not to hire that dude," said Reno Mahe, a special teams standout whom Harbaugh coached for four years. "He took this undrafted rookie and formed me into a player.
"He made me do things I didn't think I could do. In 2005, I led the league in punt returns, and 99 percent of that had to do with him."
Harbaugh "has the mind-set, the aura of a head coach," said Quintin Mikell, a defensive back. "The leadership mentality is there. He's vocal and outgoing, and if he gets on players about something, nine times out of 10 it comes from a good place.
"No matter how many times we disagree, we'll go to war for him and he'll go to war for us. You want a coach who has your back."
Harbaugh's organizational skills are unparalleled, cornerback Joselio Hanson said.
"The Ravens are in good hands," Hanson said. "All week, we got page after page of notes to read about the other team's tendencies so that, by game time, we could almost read their minds.
"With [Harbaugh], it's all about hard work and getting the most out of you. Before a workout, he likes to say, 'Let's have the best one-day practice in the history of the league.' "
Those who know him say that Harbaugh's philosophy differs from that of his predecessor, Brian Billick. Cushy workouts are out; boot camp is in.
"John makes it tough [for players] during the week but easy on the weekend," said Mike Gottfried, an ESPN football analyst who is Harbaugh's cousin.
Mikell recalled how agitated Harbaugh got last year during a hands-off drill that the Eagles practiced each week.
"It was a two-minute walk-through where the offense would march down the field, and the defense wasn't allowed to make tackles," Mikell said.
"Nobody wanted anyone to get hurt. But [Harbaugh] got ticked off because his defenders couldn't make the plays.
"Fifteen games into the season, he was still fired up about that. Every play matters to him, even in practice."
The nine years that Harbaugh spent as Philadelphia's special teams coordinator prepared him for the Baltimore job, said Sean Landeta, a former Eagles punter.
"He took a [kicking] unit that was the worst in the league and turned it into one of the best," said Landeta, a graduate of Loch Raven High. "For five years, I watched him take new guys every season and still make the pieces fit.
"He is hands-on. He can be loud. But he has an eye for seeing the little things that count, and a passion for what he does."
Passion? It's more an obsession, said J.R. Reed, the Eagles' safety and kick returner.
"In Wednesday meetings, he'd pass out pamphlets half the size of our playbooks, filled with defensive schemes for Sunday's game," Reed said. "Do you know how many trees we killed by using all that paper?
"Coach Harbaugh would have us learn the other team down to the smallest detail, like which foot [Tennessee Titans receiver] Roydell Williams starts with every time."
Where Harbaugh finds time to micromanage his game plan, Reed does not know.
"I do remember walking into a team meeting early one morning when [Harbaugh] was the only one there," Reed said. "His hair was messed up and he looked real tired."
"Get some rest," Reed told the coach.
"I'll sleep," Harbaugh said, "when the season's over."