Doucoure has been linked with a big-money move away from Vicarage Road when the transfer window opens, though the Hornets are also said to want to offer him a lucrative new deal.
"Doucoure has a long contract with us. What we can do with that, if you want to do something because a player is doing very well, that's for us to do inside the club," Silva said at a press conference, broadcast on the club's website.
"About this possibility he leaves the club, nobody talked with me about this situation.
"Our board has already given a statement that no-one will leave the club in the January market.
"What we need to do is improve our squad, not for people to leave."