The Spain international is not giving up on La Liga just yet as he is determined to get back in the title race, and believes a tough opponent awaits in the Champions League
The reigning champions currently sit third in the Primera Division table, trailing their arch-rivals by 11 points, while Atletico still hold a five-point lead, but Casillas has not given up hope of getting back in the title race just yet.
"It is a shame we are so far behind Barcelona and Atleti, but that's the way things stand and that's what we have to aim to beat," the goalkeeper was quoted as saying on the official Madrid website.
"What we need to do now is focus our attention on La Liga and the cup. We must cut the points difference with the teams above us."
Casillas then went on to discuss his side's Champions League campaign and revealed his belief that Blancos will be faced with a difficult draw in the knockout phase.
"The opponent will be tough, but there's plenty of time from now until February to get ready."
The draw for the first knockout stage takes place on December 20 in Nyon.