Milwaukee made the move Friday, retroactive to a day earlier. Manager Craig Counsell said the fracture would heal without surgery.
Counsell said Blazek struggled playing catch Thursday but didn't know how the injury occurred.
"I'm still trying to figure out exactly what happened. I'd love to tell you guys exactly what I did to it, but as of right now, I'm still trying to figure that out," Blazek said.
Blazek said the break was in the area of his small finger. He denied punching anything after Wednesday's loss.
"That's understandable. I can see why people would assume that," he said. "I understand that's how it looks. People can speculate how they want."