The Blues will head to the south coast following a damaging 3-0 home defeat to Bayern Munich.
Giroud said: "It's nearly impossible but without belief you can't do anything. Let's go to Munich with pride and we will try to score and win that game. It's going to be difficult to go through but you never know.
"For now we need to focus on the Premier League first and finish in the top four. We need to put things right on Saturday and bounce back as soon as possible."