Nelson has penned a one-year deal with Rangers and admitted reuniting with his old boss was a "massive draw".
He said: "I like his winning attitude. He and all his staff just have an absolute desire to win, and that's what the Premier League is all about.
"If you haven't got that, you won't be successful.
"The owners have got fantastic ambition and it's exciting to become a part of that.
"There is a real buzz about the place and it is a privilege to be here."