OXNARD, Calif. -- Jason Garrett, the play-caller, has operated without a "no-man" since the day Tony Sparano departed after the 2007 season.
That's about to change.
Garrett, like every good coach, needs a person who's not afraid to confront him, suggest change or inform him behind closed doors that he has lost his mind.
This is among the duties Bill Callahan, among the league's most respected assistants, signed up for the day the Dallas Cowboys hired him as offensive coordinator.
Callahan isn't going to call the plays, but he's in charge of the running game and will have more influence over Garrett than any other assistant.
As a former head coach with the Oakland Raiders and Nebraska Cornhuskers, he can relate to Garrett on a level other assistants on this staff -- no matter how qualified -- simply can't do.
Callahan can and will affect Garrett's philosophical approach to running the ball.
Garrett's teams in Dallas have ranked among the league's leaders in yards gained, but Garrett must subtly tweak his offense, and Callahan can help him do it.
Garrett respects Callahan's opinion and his accomplishments in the league. When Callahan speaks, Garrett will listen.
More important, he will act.
All you have to do is listen to the praise Garrett lavishes on Callahan, whether he's talking about the way the former head coach runs meetings or the detailed way he teaches linemen about the importance of playing with the proper leverage and pad level.
"I try to lean on our staff as much as I can," Garrett said. "I try to hear their ideas and implement them when we think they're appropriate, and Bill is no different. I lean on him every day."
At one level, Callahan's relationship with Garrett is no different than Garrett's relationship with Cowboys owner Jerry Jones.
Garrett has wielded more control than any other coach under Jerry not named Jimmy Johnson or Bill Parcells because the owner respects Garrett's intelligence and his vision for the Cowboys.
Plus, Garrett has the courage to tell Jerry what he doesn't want to hear. Johnson and Parcells are the only head coaches Jerry has hired who have consistently done that.
Just look at the Cowboys' 2012 draft class and the free agents they signed, and it's pretty easy to tell Garrett's in charge.
But he won't thrive, ultimately, without Callahan persuading Garrett to be more stubborn about running the ball.
In his four seasons with the New York Jets, they ranked among the NFL's top 10 in rushing three times. Twice, they ranked among the top five in attempts.
"The teams that win in this league are physical football teams and history will show you that," Garrett said earlier this offseason. "If you're not willing to run the ball and defend the run, you're not going to be very good.
"When you're trying to win playoff games and win Super Bowls and win championships, then you better be a physical football team."
The reality, however, is the Cowboys have had just one 1,000-yard-rusher in the past 10 seasons, embarrassing for a franchise that boasts the NFL's all-time leading rusher.
Last season, the Cowboys scored just five rushing touchdowns. Only the Cleveland Browns had fewer.
It's unrealistic to think the Cowboys will run the ball 50 percent of the time. Or even 45 percent of the time.
But they ran it only 40.1 percent of the time -- 23rd in the NFL -- despite being within eight points at some point of the fourth quarter in 11 games.
Not good enough.
Besides, playoff teams ran the ball 43.5 percent of the time, which would've ranked 13th in the league.
So we're only talking about a small percentage change.
"You have to run it to win," said Callahan, who had teams that led the NFL in rushing and passing while coaching the Raiders, "but you have to throw it to win championships."
"The running game is a process," Callahan said. "You start out in [the] first and second quarter and you may hit some single-digit runs, but I believe in the second half is when the double-digit runs begin to appear."
Callahan's task is to persuade Garrett to be stubborn enough with the running game to maximize DeMarco Murray's talent, which should make it easier to throw.
The job requires a strong-minded "no-man." Callahan can handle it.