Nottingham Forest and Derby County are investigating a post-match incident that took place after Tuesday night's Carabao Cup clash at the City Ground.
There appeared to be an altercation on the pitch following the Reds' 3-0 win over their rivals on Trentside.
It happened while Derby's substitutes were warming down and members of the Forest ground staff were tending to the playing surface.
The two managers, Phillip Cocu and Sabri Lamouchi, were both giving post-match interviews to the media at pitchside at the time.
NottinghamshireLive understands that the two clubs are currently in dialogue as they look to establish exactly what happened.
The Reds were victorious on the night with goals from Albert Adomah, Joe Lolley and Joao Carvalho as the Rams made eleven changes for the cup tie.
The win saw them progress to the next round of the Carabao Cup while their rivals crashed out of the competition.
