The 20-year-old, who has never played outside of Brazil prior to this season, joined the Hornets from Fluminense in August.
Richarlison has acclimatised remarkably well to the English game, scoring two goals in six Premier League games to help Watford into the top six of the table.
However, the youngster has spoken of how close he came to securing a move to the Eredivisie, only for a late phone call from Silva to convince him otherwise.
"I was at home, if I'm not mistaken on a Sunday night, I think," Richarlison told the Watford Observer. "[Silva] called me and told me he wanted me here at Watford, that he knew of my potential, that I could play three positions in the attack.
"And when he called me I got super happy. That day, if I'm not mistaken, I already had the Ajax proposal, everything was already agreed. Marco Silva called me then, so I changed my mind.
"I already feel at home, I feel like I'm in Brazil. My teammates welcomed me very well, especially [fellow Brazilian Heurelho] Gomes. He's the guy who helps me a lot, sorted everything for me, home, car."
Richarlison made his Premier League debut in the second half of Watford's 3-3 draw with Liverpool.