The summer signing has seen his playing time at Milan limited since the arrival of Mario Balotelli in January.
With Balotelli out injured, Pazzini returned to the starting XI against Lazio last night and scored twice to help the Rossoneri record a crucial 3-0 victory.
Pazzini believes that he can prove to be a valuable player for Milan in the final third of the season.
He told reporters in his post-match interview: "I always have to prove myself. I scored 12 goals because I was put in a position to do well and I am happy.
"We're in good shape, so must keep on picking up as many points as possible and never give in.
"We started out with two horrendous months, but then found our path and the credit goes to the players, the coach and the president."
Milan have climbed to third in Serie A after going unbeaten in their last nine league matches.