The 22-year-old midfielder found himself at a crossroads in 2012, but was not afraid to make a big career call.
With the offer of fresh terms on the table at Old Trafford, James felt regular first team football in the Championship with Leicester would be of greater benefit to his development.
He has been proved correct, with the former England U20 international now looking forward to gracing the Theatre of Dreams with the Foxes in 2014/15 - with promotion already wrapped up.
James told the Leicester Mercury: "It was a difficult decision. I was coming off the back of quite a bad injury and I didn't know where my future lay.
"United offered me a contract but it wasn't enough in terms of security. I was a little nervous about staying.
"I spoke to my family, because we knew Leicester were interested. It is a club with great ambition and tradition, fantastic support and I knew it was a Premier League club in the making. It was just a question of how long it would take.
"I knew it wouldn't take long and I thought it was going to be last season.
"I knew when I signed here I could give it a really good go and the dream has come true. It will be a little weird to run out at Old Trafford next season.
"It was always my dream to run out as a United player, but now to run out as a Premier League player will be amazing.
"It will be a great day for all my family and I am sure it will be for all the lads here as well."
James admits thoughts in the Leicester camp have already started to drift towards next season, but hopes the current campaign will end with a title-winning party at the King Power Stadium.
He added: "You are always thinking about next season, watching the Premier League games on the television and thinking we will be playing against them next season.
"It is hard not to think about next season, but we have to concentrate on this season and winning the league title.
"There are a few who have had a taste of promotion and they have been there and done it, but for the majority of us it is quite a new feeling.
"At the start of the season you would have taken second but now, having been promoted with six games remaining, it is in our hands.
"If we knuckle down like we have done all season, we will win the league and it will be a great achievement to lift that trophy on the last day of the season."