Anderson has revealed he could have joined Manchester United earlier than last summer.
The Brazil international midfielder told DiarioSport: "I could have come earlier, joining the youth team. But I broke my leg and was out of action for six or seven months.
"I did my recovery in Brazil and when I moved to Portugal (at Porto) I was told United were still interested in me.
"I never panicked and just focused on my recovery and playing well for Porto. Last summer, my agent informed me United were back trying to sign me. Everything moved very quickly."
On working with United boss Sir Alex Ferguson, Anderson added: "Sometimes he can appear distant in the press, but he is very much involved with the team, especially the young players.