The Spain international stressed that no team has ever won the prestigious competition twice in a row in its current format, and Pique feels AC Milan could cause his team plenty of problems in the quarter-finals, with the first leg to be played at San Siro on Wednesday.

"You can't call us favourites, it doesn't mean anything. No team has ever won back-to-back Champions League titles. It will be very difficult," Pique said during a press conference.

"Of course we can be eliminated. Milan are one of the greatest clubs in history. But we'll give our best, it will be a great tie."

The centre-back took time to praise former Barcelona team-mate Zlatan Ibrahimovic and fellow defender Thiago Silva, with the latter set to miss Wednesday's match with a hamstring injury.

"It was a pleasure to play on the same team as Zlatan. He's one of the best, he scored a lot and helped us to win a Liga title," he said.

"Thiago Silva is a great player, one of the best centre-backs at the moment, but Milan have a lot of great players."

Pique said he has been struggling to find his best form this term, but feels he is on his way back again.

"It has been a difficult season for me so far, after some injuries I needed the time to get into a rhythm, but I feel I'm getting there," he said.