The Spanish giants were completely outplayed by Bundesliga champions Bayern on Friday night and Pique admits the loss was unacceptable.
He said: ‘I’m in pain. We all are. We can’t compete like that.
‘It’s very, very tough to take. Nothing more is worth saying. The club needs changes. Not just the players, I don’t want to point out anyone.
‘But football is a sport where change is constantly required. We must change the dynamic we are on because I believe we have just hit bottom.
‘We have to look around, we have to trust that people will do the right things for the club. Is it an end of an era, I’m not sure.
‘But I know that we must accept that we have hit bottom. Not just players the but, as a club, we aren’t on the right road.
‘We have had years of success but we haven’t won the league and we haven’t won in Europe and we have to compete. You’ve seen it on the pitch and this today is unacceptable.
‘If I have to go in order to change things I’ll be the first to accept that. This was a horrible game… it’s a dreadful feeling. It’s shameful. Structurally we need changes at all levels.’
Goals from Ivan Perisic, Serge Gnabry, Joshua Kimmich, Robert Lewandowski and braces from Thomas Muller and Philippe Coutinho saw Bayern crush Barcelona.
Barca coach Quique Setien added: ‘It’s a tremendously painful defeat.
‘We started pretty well but the power of the opponents, in many phases of the play, overran us.
‘I’m not going to talk about what is needed at the club. I’ve been here for just a few months.
‘If Gerard Pique says that it’s time for big changes there’s going to be importance to his words. It’s time for us to review and take the decisions which are needed for the future.
‘I think that right now it’s too soon to be talking about whether I stay at the club or not. The reality is that it doesn’t depend on me.
‘It’s worth all of us working out what’s important and considering a wide range of things which correspond to a defeat of this importance and which is so painful.’