The 36-year-old could make his debut against Los Angeles FC on Saturday and says he is “hungry” to play.
Ibrahimovic wanted to join Galaxy two years ago, before eventually moving to Old Trafford.
“Finally I’m here and I’m excited, looking forward to play.
“I know it’s been a long break for me where I haven’t been in my rhythm, where I play almost every day because of the injury I had. Now I just want to go out, smell the grass, touch the ball.
“When we finished training today I just wanted to continue. I even asked the coach could I go and shoot some balls and he gave me the okay.
“I feel young. I said once before, I feel like Benjamin Button. I was born old and I will die young.
“Don’t worry about my age. I know I’m 37  but when I came to England they all said I was old, that I came in a wheelchair.
After three months I conquered England and they said I was flying. This is only numbers. I know what I’m able to do, what I will do.
“I come here to win. I’ve already brought my family. My wife can take care of the family and I can take of what I’m good at – playing football.
“We have a big game on Saturday and I’m already involved. I feel excited. The lion is hungry,” he said.
Ibrahimovic made seven appearances for Manchester United this season, scoring once.