IRVING, Texas -- The defensive messiah has a thick shock of unkempt, shoulder-length gray hair accompanied by a goatee of the same hue.
We're about to find out whether Rob Ryan can perform a miracle on the Dallas Cowboys' defense, a porous unit that allowed a franchise-record 436 points last season.
The new coordinator will have to do it with nine starters returning from last season's raggedy unit. The additions? Safety Abram Elam and defensive end Kenyon Coleman, each of whom played for Ryan's Cleveland Browns defense that ranked 22nd in the NFL last season.
We know Ryan's defense will be aggressive. And we know he's going to use some exotic looks. We don't know whether this defense will play any better.
The facts: Nine teams hired new coordinators last season, and five improved in overall total defense. Five also improved in points allowed.
Miami's Mike Nolan (sixth), the Giants' Perry Fewell (seventh) and Chicago's Rod Marinelli (ninth) elevated their units into the top 10 in total defense.
Getting a new coordinator doesn't guarantee an improved defense.
"It takes time. It's a work in progress, and we're trying to get better and better and better," Cowboys head coach Jason Garrett said. "One of the things that attracted our organization to Rob as defensive coordinator is his understanding that you have to fit your system to the personnel that you have.
"I don't believe he's one of those guys who says this is our system and by hook or by crook we're going to run this -- and oh by the way, who are the guys playing for me? That's not how this thing works."
The prognosis for the Cowboys' defense would be better if Ryan had had an offseason full of organized team activities and minicamps to implement the scheme. The lockout ruined that, so we really have no idea how the Cowboys' defense will play this season.
You can pretty much figure it's going to struggle early, and improve as the season goes and the players get more comfortable with the scheme.
As you would expect, the first-team defense has been spotty as it adapts to Ryan's system. Before the first preseason game, Ryan handed out an 8.5-by-11-inch sheet of paper filled with defensive plays.
"We had about this many last year," linebacker Bradie James said, holding his thumb and forefinger about 3 inches apart.
Garrett believes Ryan can affect the defense because he uses a complex scheme designed to create maximum confusion for the quarterback. Good communication between the defensive line and linebackers is essential because their assignments can change multiple times between breaking the huddle and the start of the play.
Don't be shocked if early in the season the big plays come in bunches because of mental mistakes. It's part of the learning curve.
Ryan will be able to do only so much this season because he doesn't have the ideal personnel to maximize the scheme. It's hard to orchestrate a defense built around the outside linebackers when Anthony Spencer and Victor Butler have yet to prove they can consistently get to the quarterback.
Sure, his dad was a fantastic defensive coach. As is his brother Rex, the Jets' head coach. Bill Belichick is among his mentors.
But in seven season as a coordinator, Ryan has had a unit finish better than 22nd in total defense just once -- his 2006 defense in Oakland finished third in the NFL. His best scoring defense was last year's Browns unit that yielded 20.8 points per game, good for 13th in the league.
"I'm confident in coaching football," he said, "but I'm not confident in singing and I'm not confident in English class or anything like that, but I'm for damn sure confident in stuff that I'm good at. I think we've just got enough arrogance to be good at this job."
We're about to find out whether that's good enough. Much is expected from a messiah.
Jean-Jacques Taylor is a columnist for ESPNDallas.com.