The La Liga champions had to come from behind to secure a 1-1 draw in the first leg of their quarter-final.
The Barcelona midfielder told reporters: "We were expecting this kind of game. We had the majority of possession and chances but they did a good job, worked very hard and managed to score a great goal. This is not a good result but we will look to win the second leg."
Atletico have not been beyond the quarter-finals in the tournament since 1974.