First-team coach Inigo Idiakez has left Derby County following the incident that led to manager Nigel Pearson's suspension, BBC Radio Derby reports.
Pearson, 53, was temporarily removed from his role by owner Mel Morris before Tuesday's game at Cardiff.
Assistant boss Chris Powell has been placed in charge for the time being.
But ex-Rams midfielder Idiakez, 42, who, like Pearson and Powell only joined in the summer, has parted company with the Championship side.
BBC Radio Derby reports that the decision to suspend Pearson was taken pending the outcome of the club's investigation into his behaviour, but he is not expected to return as manager.