This is the leader the Cowboys will follow onto the field against the Packers, a rugged 6-foot-2, 226-pound 23-year-old sturdy enough to shrug off defenders and steady enough to throw 23 touchdown passes and only four interceptions.

That he has done it all as a surprise starter is remarkable. But the fact that he has done it in Dallas — for a team owned by a man who can’t seem to stop talking about how great Tony Romo is, or how ready Romo is to reclaim the quarterback spot if Prescott somehow relinquishes it — has made Prescott’s rookie performance even more striking.

Last month, that owner, Jerry Jones, was talking so much about Romo that a former Cowboys quarterback, Troy Aikman, stepped up to question him on a Dallas radio program, saying Jones’s comments “just dumbfounded” him.

Just the thought that an owner would praise a player who could replace you might fluster another quarterback — and certainly another rookie — but not Prescott. He remained in his bubble, leading the Cowboys on an 11-game winning streak, through a disappointing road defeat against the Giants and to a 13-3 record, tying a franchise mark.

So how does an N.F.L. team happen upon a player like Prescott, whom the former Cowboys coach Dave Campo on Wednesday called “ice-cold” and “business all day long”?

Before they drafted him, in the fourth round, the Cowboys stuck Prescott in a classroom and threw different plays and different coverages at him, seeing how he would respond to changing situations and to criticism if he answered wrong. They tried to trick him into making mistakes, or into panicking. And then they studied his reactions.