The Nationals dugout during the fight. (Jonathan Newton / The Washington Post)

After Sunday’s game, in which Jonathan Papelbon grabbed Bryce Harper by the throat during an eighth-inning altercation, Nationals Manager Matt Williams was asked why he sent a pitcher who had just attacked the team’s star player back into the game to pitch the ninth inning.

“He’s our closer,” Williams said tersely, an explanation that was widely criticized and held up to ridicule afterward.

Late Sunday, in the face of mounting criticism for his move, Williams took the unusual step of calling reporters to offer a revised explanation.

The reason he sent Papelbon back in, Williams said, was that he didn’t know the details of the fight that took place just a few feet from him in the dugout.

He was at the other end of the dugout, Williams said, near the steps closest to the clubhouse tunnel, where he normally stands, when the fight broke out. It was a quick fight, over within five to six seconds, and separated by teammates and two members of Williams’s coaching staff.

Harper left the game and didn’t return in the top of the ninth. Williams did not explain why he did not send Harper back out for the ninth.

Williams said he knew an incident happened but didn’t know how serious it was. TV footage showed Papelbon talking to Harper as Harper walked into the dugout, then the two players shouting at each other and then the incident escalating when Papelbon grabbed Harper by the throat, leading to the two players wrestling.

Immediately after the game, Williams said, he went to the jersey giveaway for fans, where players and coaches present their jersey on the field to season ticket holders. Then, Williams said, he went to the press conference room to speak with reporters.

After seeing the footage, Williams said Papelbon’s behavior was not acceptable for the team.

“Now that I’ve had a chance to view the videotape, I would absolutely not have sent him back out there,” Williams said on Sunday night. “I didn’t have the luxury of viewing that at that time, with one out in the eighth inning. And I’m livid about it.”

Williams said after the game that the Nationals had not yet discussed any team-imposed suspension for Papelbon. The reliever, who apologized after the game, said he didn’t expect to be suspended by the Nationals. Although nothing has been decided yet, Papelbon could indeed face a suspension for his actions.