Gil Brandt, a former Dallas Cowboys player personnel executive who now works as an analyst for N.F.L. Media, compared Fournette to Adrian Peterson and Herschel Walker. He said that while the N.F.L. draft was heavily influenced by the positions that are perceived as important and by specific teams’ needs, Fournette “would be the first guy picked in the draft if you just say, ‘Who is the best player?’ ”

Brandt added, “He’s ready to play.”

But there is a catch: Fournette will not be eligible for the league next year. The N.F.L. requires draftees to be at least three years removed from high school, regardless of whether they are ready to play.

As a result, the soonest Fournette could suit up on Sundays is two years from now.

From the N.F.L.’s perspective, the rule helps ensure its players are up to the task. “The majority of underclassmen are not physically or mentally prepared to enter the N.F.L.,” the league states in a guide for college head coaches. “Most would benefit significantly from another year of college football.”

Rather than let individual teams size up the players and decide for themselves whether an underclassman is ready for the next level, the league codified a rule. It does not take into account that some 20-year-old sophomores — Fournette? — might be more prepared for the N.F.L. than some 22-year-old seniors.

Nor does it appreciate one big benefit for N.F.L. players: a salary.

In Fournette’s case, the rule seems to make little sense. He is already as close as it gets to a sure thing.