Police have been talking to Fleetwood Town Head Coach Joey Barton after his side's game at Barnsley on Saturday.
Officers are looking into claims the he assaulted his opposing manager, Daniel Stendel, after the final whistle.
Fleetwood lost the game 4-2.
The South Yorkshire force has confirmed it's investigating an incident in the tunnel.
Police stopped Fleetwood Town manager Joey Barton from leaving Barnsley's stadium as they investigated the alleged assault.
Footage showed the former England and Manchester City footballer being driven from Oakwell Stadium before an officer stood in front of the vehicle to stop it.
It comes after Barton and Barnsley manager Daniel Stendel reportedly had to be separated by stewards in the tunnel after their teams' League One match on Saturday.
It's understood South Yorkshire Police have spoken with Barton, and will speak to him again later in the week as part of a voluntary interview.
Barnsley said in a statement: "The club can confirm there was an alleged incident in the tunnel area that took place following the conclusion of today's match, which South Yorkshire police are currently investigating.
''The club is assisting the police with its enquiries and, as a result, we are not in a position to make any further comment at this time."
Fleetwood Town have also issued a short statement that said: ''Fleetwood Town have been made aware of an alleged incident following Saturday’s game against Barnsley.
''We are currently establishing the facts and will not make any further comment at this time.''