The 21-year-old Nigerian forward was arrested on September 11 following an incident at Sopwell House in Hertfordshire.
Success joined Watford for £12 million from Spanish club Granada in August 2016, but scored just once in 19 appearances for the Hornets last term.
He has featured in only one game this season - as a second-half substitute in Watford's 3-2 defeat against Bristol City in the Carabao Cup in August - and now faces eight weeks on the sidelines following a knee injury he sustained in training.
"The player and everyone knows the obligations at this club and he knows the rules," said Silva, who refused to reveal whether Watford would discipline the forward.
"Of course people who love football don't like this situation. Football is his life. He needs to be careful - everyone needs to be careful - and know the right way. What we are talking about is one situation in September.
"I'm really happy with his improvement. He has not played more minutes as I had to make different changes in games due to injuries. I am happy with his progress and the player is starting to understand what my way is and what he needs to do to have minutes.
"Our obligation is to put the player in the right way. But you can't do this every time. He is a young player and he knows."