The Rossoneri striker made an instant impact following his move from city rivals Inter Milan by single-handedly deciding a 3-1 victory at the Renato Dall'Ara with a clinical hat-trick.
That result would prove to be false dawn, though, as Milan went on to lose seven league games in the first half of the season, while Bologna slowly stabilised themselves in mid-table.
The revised target is a European berth and Massimiliano Allegri's men could take sixth place from Roma with another positive result against Bologna.
Pazzini told the Corriere dello Sport: "I have great memories of the first time we met and it was a great game.
"But Bologna are enjoying a good run of form and it will be tricky going up against them. I hope some of that brilliance has worn off a little after they played 120 minutes against Inter in the Coppa Italia.
"When you are behind, you have to catch up and recover the points. It's no surprise that there's a bit of regret about the way we started the season.
"But now we have almost an entire second half of the season in which to pick up as many points as possible.
"We need to make sure we have no regrets in May, knowing that it does not depend entirely on what we do."
Real Madrid forward Kaka is poised to return to the club where he made his name, as Milan vice-president Adriano Galliani revealed talks are taking place over a potential loan move.
The Brazilian is unlikely to be registered in time to face Bologna, though, with midfielders Nigel De Jong and Massimo Ambrosini missing through injury.
Henry Gimenez, Cesare Natali, Saphir Taider and Robert Acquafresca provide injury concerns for Bologna, who have drawn once and lost this fixture twice from three recent attempts.
The Felsinei atoned for two straight defeats by trouncing Chievo 4-0 last time out, moving four points clear of the relegation places in the process.