McTominay had been with the Red Devils for 22 years, making 255 first-team appearances in a period of mixed success for the club. Now, speaking to the BBC he opened up on the move that he admits was not a difficult choice to make.
"I saw the passionate fans, I saw the coach, I saw the players and I saw an opportunity.
"I took it. I didn't look back. It didn't take me long to make the decision because I knew that was what I wanted and I'll never have any regrets in my life. As soon as I put my mind to something I want to do it, that's it. There's no holding me back."
The Scotland international admits all parties understood his time with the club had come to an end and that the project presented by Napoli inspired him to put pen to paper.
"It was a mutual decision. It was a case of - there's an opportunity there, do you want to go?
"Obviously I know from their side FFP is difficult. It's not easy for clubs to make a decision in regards to homegrown players, but that was never in my thought process.
"My thought process was coming here, seeing the fans, the coach and hopefully doing really good things.
"On my last day, I had to go and see everyone and it was not easy to say goodbye. But that's football. That's the life. I spoke to him (Ten Hag). He expressed his thoughts on the situation. I said, 'listen it's my career, I am here to push myself on'.
"In this situation, I have to look out for number one and go with my gut feeling of what I want to do in my career and not be held back by any other external factors.
"It was amicable. I love that football club to bits, they have been my life for 22 years, but I have moved on now. I am thoroughly enjoying myself here."