Nigeria’s Isaac Success has been warned by Watford coach Marco Silva about his conduct at the Premier League side.
The 21-year-old striker, who is currently injured, was detained by police last month following an incident at a hotel in Hertfordshire.
“He needs to be careful – everyone needs to be careful – and know the right way,” said the Portuguese Silva.
“Everybody at the club knows the rules and their obligations as a professional.”
“What we are talking about is one situation in September,” added Silva, who refused to reveal whether Watford would discipline the forward.
Success joined the Hornets for a then club-record fee of £12.5m from Spanish club Granada in August 2016, signing a five-year contract.
He managed just one goal from 19 games last season, netting against Bournemouth over a year ago, and has yet to feature for Silva in the Premier League this season.
However, he now faces eight weeks out with injury following a knee injury sustained in training.
“We expect six to eight weeks,” said Silva. “It’s a knee injury, a problem he had in one session here.”
“It was a normal situation and looked nothing special at that moment but after examinations, the problem is bigger and now we need to wait for him.”
Success’ sole appearance for Watford this season came as a second-half substitute in their 3-2 defeat by Bristol City in the Carabao Cup in August.