Through eight weeks, the 21-year-old Darnold has completed 55.2% of his passes and thrown for 1,705 yards with 11 touchdowns and 10 interceptions. The 6'3", 225-pounder, who has displayed a veteran presence and approach to the game, is still learning the nuances of the NFL.

"The key for him will be nothing more than learning football," Romo said. "Studying after the game as much as before and your ability to go back and think about why you did that, why your brain thought this, why in that moment you decided to do this and always evaluate your thinking. You'll eventually be teaching yourself how to think as much as you are about where to go with the football."

Dating back to his three-year collegiate career at USC, Darnold has been lauded for his mental makeup and resolve. But according to Romo, the rookie's spatial awareness between the white lines is what makes him special.

"The really great ones get through progressions really quickly. They can sense leverage and spatial awareness where you can get off a receiver before they're even at the top of their route because you can already see what's going to happen," he said. "That way you get to the third read in one second where someone else is waiting.