The Ivory Coast international has struggled for much first team action in recent times but was on hand to help the Blues to a 4-1 win in the FA Cup over Cardiff City on the weekend, scoring as a substitute.
Despite not playing as much as he desires, Kalou knows it is important for Chelsea to have a strong bench if they want to be successful.
"I haven't been playing lately and to get in the team and score a goal is very important for my confidence," he said.
"You can build a lot of confidence for the next game from it.
"That is how you win prizes. You need to have a strong bench, people who can come on and turn a game around.
"We always go for every competition and it is a good feeling to still be in the FA Cup.
"We know the other top three clubs are out and there is a good chance for us to continue to try to win it again."