The German giants defeated HSV 9-2 at home in the Bundesliga, with the Peruvian striker scoring four goals.
"It was a Bundesliga game, but I think it also served as a preparation for Tuesday's game which gives us confidence," Pizarro told Bundesliga.com. "We think we can play another good game on Tuesday.
"Yes, I think so too [that it will be more difficult against Juventus]. But if we can get a goal, then maybe they will open up a bit at the back.
"Maybe we can then take advantage of that and get a few more goals. That would be important for the [return] match in Turin."
Bayern will host the first leg of their quarter-final tie at the Allianz Arena on Tuesday.