The Scotland international has thrived in his first season in Serie A under Napoli coach Antonio Conte.
Recalling the Azzurri's initial approach, McTominay told La Gazzetta dello Sport: "I had heard about it during the European Championships and there was an immediate attraction.
"When this opportunity came, I took it seriously. Instantly. It had never happened to me before. I wanted to be sure it was the right decision at that time and for the future, so I informed myself well about the project, the team and the coach. And the sporting director Giovanni Manna had a great influence on me, helping me.
"He came to my house in Manchester, we had a very pleasant conversation: he explained to me the culture, the history of the club, the shirt and Napoli, its wonderful stadium. The passion of the fans, the myth of Maradona, the food which is incredible.
"And obviously the opportunity to be able to win important trophies that would make my career grow. Here I am very happy and I want to continue to do my best on the pitch."