Richarlison is closing in on signing a new five-year contract with Everton.
Blues’ director of football Marcel Brands announced last week that they had agreed an improved deal in principle with the Brazil international representatives.
Although the extension only adds a further 12 months on Richarlison’s current deal, which has four years remaining, it will safeguard his long-term future.
Marco Silva has revealed that Manchester United are among a number of clubs that have been tracking the 22-year-old in recent months with a view to a move.
He said: “I believe it is not just Manchester United. I believe it is some more.
“As a club we have to keep our best players.
“Unfortunately we did not keep one of them in the summer [Idrissa Gana Gueye] but to keep growing and going in the right way we want our most important players, our best players, and we should keep all of them.
“Then we can keep growing. We don’t see other clubs who want to grow selling their best players. That is what we should do.”