The Gunners are preparing for Wednesday's Champions League Round of 16 second leg at Bayern Munich, which they will go into trailing 3-1, and Giroud has implored the defenders to avoid making simple mistakes.
"We need to score an early goal," Giroud told Kicker magazine.
"In football you never know. We need to believe and stay focused.
"But we need to correct our bad defensive behaviour as well."
Giroud added that he feels Arsenal, and himself, may get some scoring opportunities at the Allianz Arena.
"I like to play against German teams because they are attacking all the time. There I get myself more possibilities to score," he additionally said.
"It will be an interesting game for sure."