While changing a screen on the prescreener. ELJ 6x20 2 deck. His finger got caught between the screen and the frame. Was wearing gloves, did this procedure 20-25 times. Did not want medical treatment at the time. Went to ER for flu symptons. While there dr x ray finger and said it was broken. His finger was put into a splint. We found out it was broken 9:00 pm next day.