Advertising executives described the N.F.L.’s action, reported by Reuters on Wednesday, as extraordinarily unusual. The ad was produced and subsequently edited by the Saatchi & Saatchi agency.

“It’s not unheard for a spot to be changed after launch, but it’s usually after a portion of the public takes offense to something in it,” said Mark DiMassimo, chief creative officer for DiGo, a New York-based advertising agency.

The football commercial was one installment of Toyota’s “Ideas for Life” campaign depicting how Toyota’s automobile safety research could apply to other fields.

Ziegler, the Toyota spokeswoman, said that the edited commercial was scheduled to run through this week, but that she was unsure whether it would run during one of Sunday’s conference championship games. She added that Toyota had already planned not to advertise during the Super Bowl on Feb. 6 because it is not unveiling a new vehicle.

McCarthy, the league spokesman, said the N.F.L. also had Toyota “tone down the crunching,” which he described as sounds Saatchi & Saatchi had manufactured and dubbed to enhance the footage of colliding players.

“You wouldn’t hear that on a football field,” McCarthy said.

The collision in the commercial would almost certainly have been considered legal on an N.F.L.  and high school  field. Players are generally penalized for hitting the heads only of defenseless players, such as a quarterback throwing or a receiver in the process of making a catch.

After several high-profile incidents last October, Commissioner Roger Goodell began fining players up to $100,000 for such infractions, regardless of whether they were flagged by an official.