The teenage centre-back, who joined the Blues from Brondby in July 2012, made his debut for the Europa League champions in an end-of-season friendly against Manchester City in the USA in May.
He was then awarded a contract extension following the arrival of new manager Jose Mourinho.
"I am happy and proud to play at such a big club like Chelsea," Christensen told Danish newspaper BT. "Things are perfect.
"I hope during the season I get some more first-team appearances. But I am patient and take it slow. I'm young and ready to wait for my breakthrough.
"Jose Mourinho often asks me to show up to first-team training. At first I was a little confused about playing alongside John Terry, Fernando Torres and Samuel Eto'o, but not so anymore. They have been really good to me."
Christensen has represented Denmark at Under-21 level.