While backing down spoil to get another push with dozer, I.E. ran over rock that employee did not see come from a wind row of the previous push. Dozer jerked after hitting rock jarring the employee's neck. I.E. has worked until taking a week off for pain from 4-20-2020 to 4-23-2020. I.E. is back to work. I.E. did not report the injury to the operator until 4-27-2020.