Employee was removing the hydraulic pump of an excavator. EE told me that oil had spilled on the tracks and they had fallen. EE told me they were fine. When I left EE was working on a truck tailgate. The next morning, EE called in sick. On 9/10/18 EE was seen at St. Charles ER and diagnosed with broken ribs. EE was cleared to return to work on 9/13/18.