"I tried to talk, but I couldn't. Then I started to feel the pain from inside," Herrera said Sunday, a day after getting hurt during Milwaukee's 9-7 loss to Cincinnati. "I really was thinking that something was wrong, something was broken."
With two on and two outs in the eighth, Skip Schumaker hit a looping fly ball down the left-field line. Herrera chased the ball along with shortstop Jean Segura and Peterson, who was in left field. Herrera and Peterson collided, and the ball fell between them.
Herrera did not move for more than five minutes while he was treated by Brewers trainers. He was rolled onto his back, was put on a backboard and stretcher and left the field in an ambulance. He was diagnosed with a deep thigh bruise.
Herrera was on crutches Sunday and said he is not sure when he'll return to the lineup.
"I know a couple of days, for sure, because it's really painful right now, and I can't really stand," Herrera said.
After his knee was examined, Peterson remained in the game.
Brewers pitcher Jimmy Nelson was struck on the head by a line drive during a game against St. Louis on Thursday. Nelson, who sustained a bruise, spent two nights in a hospital for observation and was released Saturday.
"We dodged serious injuries. Some scary looking plays for sure," Milwaukee manager Craig Counsell said. "It's been a rough week."