Girardi said on Friday that he watched tape of Duncan's spikes-high slide into the Rays' Akinori Iwamura from Wednesday's game, and he believes Duncan's version of the events. Duncan said he was trying to kick the ball out of the second baseman's glove in an attempt to stretch a single into a double.
"The way he reacted when he slid leads me to believe that's what he was trying to do," Girardi said. "If there was malicious intent, I think he would have popped right up. Shelley laid there."
The Rays saw things differently. Duncan's slide opened a cut over Iwamura's right knee, and Tampa Bay outfielder Jonny Gomes charged into the play, hitting Duncan from behind and setting off a benches-clearing incident in which four were ejected.
The Rays and Yankees are scheduled to meet again in a split-squad game on Saturday at Legends Field in Tampa, Fla. Duncan has been listed on the Yankees' roster for that game, despite New York also playing a road game against the Tigers in Lakeland, Fla.
Girardi said he would not hold Duncan out of the lineup out of fear that the Rays might retaliate.
"I'm trying to move on," Girardi said. "Shelley's play was aggressive. I don't think Shelley tried to hurt anyone. Other people may see if differently. He's going to have to play against the Rays someday."
Girardi said he anticipated the umpiring crew issuing a warning before Saturday's game. Tampa Bay manager Joe Maddon has also said that he will make the trip to the game against the Yankees; the Rays also have a split-squad game against the Braves in Lake Buena Vista, Fla., on Saturday.
Duncan has said repeatedly that he plays the game the way he learned it in clubhouses growing up. Girardi said that he has no intent to attempt to change the way Duncan plays, despite the recent events.
"I think Shelley is a guy that plays hard, and it probably rubs some people the wrong way," Girardi said. "But it doesn't rub us the wrong way. We want him to play hard."
Bryan Hoch is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.