(David Goldman/AP)

The hiring of former FBI director Robert S. Mueller III to investigate the NFL’s handling of the Ray Rice case throws the controversy into a new and unpredictable phase that could lead to severe sanctions against NFL Commissioner Roger Goodell, former FBI officials and people close to NFL team owners said Thursday.

While Goodell continues to have solid support among many of the NFL’s 32 owners, the owners are prepared to act against him, potentially considering his dismissal, if Mueller’s probe concludes he misrepresented what he knew about the Rice investigation or orchestrated a cover-up, several people familiar with the owners’ views said.

“He’s been a very good commissioner, and he’s done great things for the league,” a high-ranking executive with one NFL team said. “The presumption is that he’s telling the truth and the investigation will demonstrate that. We’ll go by the report [generated by Mueller’s investigation]. If the report says something different, we’ll take the appropriate action.”

Mueller was asked by the NFL on Wednesday to handle the investigation following a report by the Associated Press that contradicted the league’s insistence that no one in the NFL office had seen a video of Rice strike his then-fiancee in an Atlantic City casino elevator until Monday, when it was published by the Web site TMZ.

Rice, a former Baltimore Ravens running back, was dismissed by the team and indefinitely suspended by the league Monday.

The Post Sports Live crew discusses Ray Rice's release from the Baltimore Ravens and his suspension from the NFL after new video surfaced of a domestic violence incident involving the running back and his wife. (Post Sports Live/The Washington Post)

Former FBI officials said Mueller was chosen because he does not have close relationships with the NFL’s front office. “He had none,” said a former FBI official who worked with Mueller, speaking on condition of anonymity.

“They know what they are getting when they get Bob Mueller,” the former official said. “Goodell could be signing his own exit. Mueller is not going to hide anything. He is a straight arrow.”

James W. McJunkin, a former senior FBI official, said Mueller’s “integrity is unquestioned.”

“He’s going to be thorough,” McJunkin said. “He’s going to put everything on the table. God knows he won’t be afraid to point out mistakes. He pressed us every single day.”

Mueller’s investigation will focus, at least initially, on a copy of surveillance camera video footage taken from inside the casino elevator that a law enforcement official told the AP he sent to NFL headquarters in New York in April. The official also played for the AP a voice-mail message from an NFL office phone number in which a female voice confirms receipt of the video.

Though Goodell enjoys the support of the team owners for now, the discovery of any role in any deception perpetrated during the investigation into the Rice case could cost him dearly, officials familiar with the owners’ thinking said.

“If the investigation concludes that the commissioner saw more and knew more than he has said and he was not truthful about that to the clubs, things would change,” said a team official who had been briefed on the views of the owner of his franchise.

A top executive with a third franchise who had spoken to his team’s owner expressed similar sentiments, saying Goodell’s job would be at risk only if it is found he personally orchestrated a cover-up. “Certainly he would be [held] accountable for intentionally misleading people and taking actions to cover his tracks,” that executive said. “Certainly that would be grounds for anything from a reprimand to termination. [But] it would take a lot. No one expects it to come to that.”

According to that executive, owners would have little choice but to consider firing Goodell if Mueller’s report concludes Goodell acted improperly in a significant way.

“The integrity of the league would have to be protected at a certain point,” the executive said, relating what he called the thoughts of that team’s owner. “The trust of the public would have to be maintained. But, again, that’s not the expectation here.”

Two league owners, the New York Giants’ John Mara and Art Rooney II, the president of the Pittsburgh Steelers, will oversee the Mueller investigation. They said they had spoken with Mueller on Thursday and that the former FBI chief would launch his probe immediately.

“No timeline was established, and we stressed that he should take as much time as necessary to complete a thorough investigation,” Mara and Rooney said in a statement. “We agreed that the scope of the investigation should be aimed at getting answers to specific questions, including what efforts were made by league staff to obtain the video of what took place inside the elevator and to determine whether, in fact, the video was ever delivered to someone at the league office, and if so, what happened to the video after it was delivered.”

Mara and Rooney said they will not participate in the investigation but rather facilitate the efforts of Mueller.

“Mr. Mueller assured us that his investigation will be thorough and independent, and that he will keep us informed of his progress,” the statement read. “Our sole motive here is to get the truth and then share Mr. Mueller’s findings with the public.”

Mueller will lead the investigation but will be assisted by Aaron M. Zebley, another former FBI agent and federal prosecutor who was Mueller’s chief of staff at the bureau. Zebley is now a partner at the law firm of WilmerHale, where Mueller landed after leaving the FBI.

Despite calls for him to step down by the National Organization for Women and others, Goodell has remained adamant he did nothing untoward and will not resign, according to people familiar with his thinking. One of those people said Wednesday night, following the AP report, that Goodell “never” will resign and there’s “no reason to.” Goodell told CBS News this week he did not believe his job was on the line.

adam.goldman@washpost.com