Club officials said they would not know how long he'll be sidelined until Sunday, when he sees a hand specialist in Los Angeles.
Ethier, who leads the league in average (.393), home runs (11) and RBIs (38), said he suffered the injury on a swing.
"It was a freak thing," he said. "I was in the cage hitting and I've done this a few times, where my finger gets pinned under the knob of the bat and it gets sprained or bruised. This time it gave way. I kept swinging three or four times and thought it was sprained. I went to the cage and it started throbbing a little bit.
"I went out to play catch and it blew up a little more. I tried to hold a bat and it didn't feel right and I told Donnie [Mattingly, hitting coach]. It's right at the leverage point of my swing. I guess my finger kind of slipped when I threw the knob and it got contorted."
X-rays revealed a fracture of the first knuckle of the right pinkie. Manager Joe Torre called the fracture "small," but trainer Stan Conte would not detail the injury or offer an estimate for recovery until Ethier is examined by team doctor Neal ElAttrache and hand specialist Dr. Steve Shin.
"They told me fracture, and I didn't even look at the X-rays," Ethier said. "I didn't want to see it. It could be a couple of days. It could be longer. We'll see what they say tomorrow.
"I'm disappointed. I've had a lot of other things bother me a lot more this year, the ankle [sprained the first week], the knee [hyperextended the final week of Spring Training], then to have something this small, a hiccup, it's frustrating."
Torre reserved judgment until he learns how long Ethier will be sidelined.
"It's something you certainly don't want to have happen," he said. "When the season doesn't give you a chance to breathe, you just move on."
Ethier was leading the Major Leagues with a May average of .490, a .980 slugging percentage and 19 RBIs. Tuesday night at Dodger Stadium is his bobblehead night. Said Clayton Kershaw, Saturday night's winning pitcher, upon hearing of Ethier's injury:
"It stinks, honestly. The best player in the game, the best hitter for sure. It's definitely not something we're excited about. He's going to be sorely missed. But you saw tonight, we can win without him. I don't think you ever replace a guy like Andre. Good pitching beats good hitting, so we're going to have to get good pitching."
Triple-A outfielder Xavier Paul was removed from Albuquerque's game Saturday night in the third inning, but Torre said that was because Paul had been hit by a throw and did not mean he was being recalled to replace Ethier.
Ken Gurnick is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.