X-rays of Ethier's ankle were negative, but it was swollen and sore. He was being treated by the medical department, and manager Joe Torre said he did not know how long Ethier would be out of the lineup.
"He's got some discomfort," said Torre.
After Thursday's game, Ethier said the ankle was improved but still sore. He said he didn't expect to play Friday, but was hopeful he could return by Saturday. He said he hasn't had an ankle sprain since high school.
Ethier rolled the ankle stepping back onto the first-base bag in the fifth inning after a pickoff attempt by Pittsburgh starter Ross Ohlendorf with Manny Ramirez at bat. Ohlendorf made five attempts to pick off Ethier that inning.
Ethier continued to play after the injury, going all 10 innings Wednesday night.
Ken Gurnick is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.