He said: "Northampton are one of the best teams in the Premiership. It will be a big challenge for us to get a win but we have to be confident in ourselves.
"We are at home and we need to do the things we are good at. Our forward pack has looked strong in recent weeks but we need to raise the level again on Saturday."
Galarza arrived at Sixways in October and has gone on to make five appearances for Dean Ryan's men.
His arrival has coincided with improved performances from the forward pack and the 26-year-old admits he has settled in well at the club.
He continued: "I am really enjoying it here. I give everything I have for the team because I want to help change things here and make the team successful."
Galarza was in action for Argentina against England and Italy during the recent autumn internationals and he admits his believes his country are also moving in the right direction.
He added: "I enjoyed the time with Argentina. Against England we struggled in the first-half but were a lot better after the break.
"Our last game against Italy was not a classic but we needed a victory so we were delighted to come out on top.
"We are building a team for next year. We have a lot of young players and a new coach so we're focused on the future, like we are at Warriors."