Atletico Madrid midfielder Mario Suarez has praised the club's supporters for their backing this season.
The capital outfit top La Liga by four points with just four games remaining as they chase their first league title since 1995.
"As the coach says, we face another final. It's an important game for the club, for us, which we have to play over two legs to get to a final," Suarez told reporters.
"We know that in this kind of time the first game is always important and we play at home with our fans, who are our 12th man.
"When I was in the cantera and went to the ground to cheer the first team I never had the opportunity to do it in a Champions League semi-final."
The first leg against Chelsea takes place in Madrid on Tuesday evening.