Barcelona sporting director Eric Abidal has opened up on their Champions League semifinal collapse against Liverpool last season.

After winning the first leg 3-0, Barcelona lost 4-0 in Liverpool which left many questions to be answered.

"I will speak about the first leg first," Abidal told Sport. "All Barça fans will surely remember more the result of that game. It was really difficult and the final result is not reflective of the game. It was a clear warning of what could happen."

In his opinion, the disaster at Anfield was down to "the attitude of the team and (not scoring) a goal. We lacked a goal. With one goal, no one would remember (what happened in) Liverpool. That's what I had in my mind in the stands. It had to happen."

Abidal believes that the Liverpool loss was "a different accident to Roma. They're not equal rivals and the games weren't the same. Liverpool was not Roma. You learn from it, but you have to think that the difference was one goal. And that one goal marked the season."

He shared out the responsibility for the result: "It's joint between the players and the coach. It was an accident. Things happen in football that you can't explain. Not even the players that were playing the game."