The 69-year-old Italian is adamant that the San Siro giants will be a force once they get all of their players back from injury
Massimiliano Allegri's men have endured a difficult start to the season, picking up just five points from their opening five Serie A fixtures.
However, injury-ravaged Milan battled past Samp at San Siro thanks to a first goal for the club from Valter Birsa, who joined from Genoa as part of the deal that saw Luca Antonini move in the other direction.
"The Birsa-Antonini deal came late in the transfer window and has done favours for all involved," Galliani told his club's official website.
"Birsa scored this evening and Luca Antonini scored in the derby for Genoa. Birsa can give his contribution in this difficult start to the season.
"So, the glass is half full: we are scoring all the time and if we can stop making mistakes at the back, especially in set pieces, we will win a lot more games.
"Now we have to get points against Ajax in Amsterdam [in the Champions League]. When we get all of our players back we’ll be in better shape."
Meanwhile, forward M'Baye Niang, who came off the bench to replace Birsa, is hoping that he can prove a worthy replacement for the injured Stephan El Shaarawy and the suspended Mario Balotelli in next week's mouth-watering clash with reigning champions Juventus.
“I came on and I did well this evening. It’s not easy to come off the bench but I tried to get involved immediately because the team needed energy," the Frenchman said.
"I’m here to work hard and to become the player that I want to be. El Shaarawy and Mario are both really important players but they’re not available so we have to do without them. But we have other players with potential.
"I have to go to Turin with the desire to do better than last year and I hope to score. When the team needs help, I like to be the one to help out.”
AC Milan now sit in eighth position in Serie A, having racked up eight points from their first six matches.