Two employees were positioning a roll body on the floor in the vertical position to remove the profile sleeve. Once the roll body was positioned, an employee started to remove the lower drive key retaining bolt with a hex key. He was kneeling on the floor next to the roll body with his right hand resting on the side of the sleeve and his left hand operating the hex key. When the retaining bolt came loose, he lost his balance and his right hand moved to the floor to stabilize himself. As the retaining bolt and key fell out, the sleeve slid down the roll body to the floor, striking the employee's right hand. He suffered broken bones in the backside of the hand and a minor laceration when he pulled his hand out from under the sleeve.