Hall hurt the ankle when he scaled the 10-foot wall in center trying to grab Ryan Doumit's home run. After the home run was safely out of his reach, he let go of the wall and landed awkwardly on his right foot and fell to the ground.
"I didn't realize how high I was," Hall said. "I was prepared to land a little quicker than I was, and once I didn't, the ground kinda snuck up on me.
"Everything was good except for the landing. I got up there, I saw where the ball was, picked a spot with my glove and got pretty close to it, actually."
He was helped off the field by two Brewers personnel, and was walking with crutches and a protective boot on his right foot in the clubhouse after the game.
Brewers manager Ned Yost and Hall both said they didn't know the severity of the sprain or how much time Hall will miss.
"I guess I'll have to wait until [Friday] to see how much swelling [there is]," Hall said. "Hopefully I'm a quick healer."
Geoff Jenkins entered the game for Hall and played left field. He went 2-for-3 with a two-run home run. Corey Hart moved from right to center and Kevin Mench moved from left to right.
Jeremy Anders is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.