The Argentina international's future at the Etihad Stadium looked bleak in September when the 28-year-old refused to come off the bench during a Champions League match against Bayern Munich, which later snowballed into the forward's abandonment of the Premier League outfit.
Despite Tevez's fall from grace, the frontman has returned to Man City in an explosive fashion, netting four goals in City's last three victories.
"It's clear that with him we would have had a better chance," Mancini told France Football. "But we were top of the league until March, which means the other strikers did well. I always had a good rapport with him. I didn't have a problem to forgive him.
"The board have never imposed anything on me. To play Tevez again was a logical choice because he didn't leave in the January transfer window. He's a player of great quality, one of the best strikers in the world, and we thought he could help us.
"I have had a good attitude with him like with everyone else. It's not us who wanted him to go to Argentina November. I was very sorry with that situation. I found it strange. I don't know why all this happened."
The controversial star is expected to star in City's crucial clash against Manchester United at the Etihad Stadium on Monday.