Alex enjoyed his 100th appearance for Chelsea in the victory over Bolton Wanderers.
The Brazil defender has fought back after an injury-plagued campaign.
"I played 20 games this season? I need to play more!" he told chelseafc.com. "It is a big difference, this is good! It is not because of me, it is difficult to explain but in the last five games we played very well, and did not concede goals.
"We have more confidence to play and we want to put this on the pitch. It is difficult but the responsibility is good and playing with Chelsea is very good for me, I have confidence whoever I play with in the team."