The 35-year-old left Paris Saint-Germain for Old Trafford last summer and scored 28 goals in his maiden campaign in English football.
However, Ibrahimovic's season was curtailed by a serious knee injury in April, but five months on, the striker is making impressive progress in his recovery from knee ligament damage.
The Swede, released by United at the end of last season but re-signed in August, told Sky Sports News: "I feel good. I have trained every day since I had my knee operated on, there is no vacation.
"It's a new challenge but I am strong mentally and when I focus on an objective nothing can stop me. I will go through everything, it doesn't matter what's in my way, I will break everything to reach my goal.
"When I come back to play football on the field I will be better than before, I am not coming back because I am the one I am, I am coming back to be a better version of the old one. Imagine how that will be!"
Ibrahimovic, who stopped short of giving an estimated return date, has been named by Jose Mourinho in Manchester United's squad for the Champions League group stages.