FLOWERY BRANCH, Ga. — Atlanta Falcons General Manager Thomas Dimitroff, his hair spiked and his shoulders often hunched over racing bicycle handlebars, has a youthful bearing that might connote impetuous decision-making without the benefit of historical context.

But for Dimitroff, the engineer of the boldest player transaction in an N.F.L. off-season filled with them, the notion of paying a king’s ransom for one college player who was not the consensus leading pick at his position began brewing soon after Atlanta hired him.

Dimitroff, 45, caught wind of wide receiver Julio Jones in 2008, when he was the Southeastern Conference freshman of the year at Alabama. In time, he grew smitten with Jones’s skills, admiring of his grit, blown away by his humble nature.

“The fact that he was as talented as he was on the field, sans the diva qualities you sometimes have at that position, was very attractive to this organization,” Dimitroff, who has 22 years in player evaluation, five as the director of scouting with the New England Patriots, said last week.