The league considers the draft an entertainment event that galvanizes its fans during the off-season with information that it wants to control.

“We want to present a compelling experience that keeps people coming back — the fans in the theater and the millions watching,” said Brian McCarthy, a league spokesman. Reporting on draft picks minutes or seconds in advance by insiders like Schefter, Jason La Canfora of CBS Sports and others “detracted from the overall viewing experience.”

He said that fans interviewed by the league in focus groups had also voiced their displeasure at learning of the picks in advance. Asked whether the N.F.L.’s action amounted to directly managing reporters’ journalistic work, McCarthy said: “Underscore ‘network partners,’ which is part of being associated with the N.F.L. We have language in our contracts that protects against this type of activity.”

The N.F.L. is not the only league that has seen itself lose some control of a rigid draft narrative. A pick is transmitted from a team to the league, and a commissioner, or some other official, announces it. But Twitter has short-circuited that system by letting reporters with strong sources post their news almost instantaneously. Adrian Wojnarowski of Yahoo Sports has made the N.B.A. draft his Twitter playground, routinely beating other league reporters to name picks before Commissioner Adam Silver reads them to the audience watching on ESPN.

“I don’t care about anybody’s television show,” Wojnarowski said. “My job is to report and break news when I have the news, and who a team is drafting is news. The draft and the announcement is a ceremony. I don’t care about anybody’s ceremony. I don’t wait for things to be announced. I would never accept any edict not to report the news.” He added, “I see it as an extension of free agency and the trade deadline. If your information is accurate, you want to report it.”

The N.B.A. restricts its network partners and announcers involved in its draft production from revealing picks in advance, but it does not prohibit its reporters working independently from doing so.