One goal is all it takes to seal place in last eight...
The west Londoners are 2-1 down from the first leg in Italy, but Kalou feels confident that Chelsea can score the goal they need to secure victory in the tie.
"We expect a difficult game, because they're going to come back. We know what Jose Mourinho is about, we know that when he needs to keep the result he's very good at it," he told UEFA.com
"But in the end we have the opportunity to win at home and we know better how to play at home, so we're really confident about that.
"We know we just have to score one goal to qualify."
Kalou scored the crucial away goal in the first leg at the San Siro, and the Ivory Coast international relished the occasion.
“It was a great moment. It was my first time at the San Siro, the first time I have played in that unbelievable stadium," he said.
“It was very important for me to score and get the confidence back - and to get back in the team. I felt happy. I felt good.
“It showed the confidence [manager Carlo] Ancelotti has in me, to start me in such a big game after not playing for a while. I always get myself ready for every game, to try to do my best, to try to bring that extra thing to the team.
“Any time I have the opportunity to get on the pitch I enjoy myself, and I try to push my team to victory."
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