Everton manager Marco Silva says he is “not happy” with Jordan Pickford after the England goalkeeper was allegedly involved in a street fracas.
A video published on social media appears to show the 25-year-old involved in an incident outside a Sunderland pub.
“No-one is happy with the situation – it was not a good thing,” Silva said.
He said players had “duties and obligations” and the club would need to remind Pickford of what they are.
“If you ask me as a manager I am not happy with what happened,” he added.
Silva went on: “Everything we must do we already did. It is my expectation it won’t happen again.
“The first chat of the week I was clear with [Pickford]. Everything is clear in his mind about his obligations.
“The matter is finished in this moment.”
On Tuesday, Northumbria Police opened an investigation following the “disturbance” on Monday night.
“At 12:19am (Monday), police received a report of a disturbance involving a large group of individuals on Tunstall Road, Sunderland,” a spokesperson said.
“Enquiries are ongoing to determine the circumstances surrounding the incident and locate those involved.”
They added: “Nobody is believed to have been seriously injured and no arrests have been made.”
England’s first-choice keeper Pickford played on Saturday as the Toffees beat West Ham 2-0 at London Stadium.
Everton next face Arsenal in the Premier League on Sunday at 14:05 BST.