Former AC Milan coach Arrigo Sacchi said he believes Barcelona have hit a brick wall after their 4-0 Champions League humiliation at Paris Saint-Germain.
The thrashing left the Catalan side facing a round-of-16 elimination for the first time since 2007.
Sacchi -- who spent time in Spain as Real Madrid's director of football and also coached Atletico -- praised Barca's success over the last decade but suggested losing their principles had led to the humiliating defeat.
"For some time, Barcelona have not been the old Barcelona," he told Sport.
"Even in La Liga they beat the weak clubs with ease but struggle with stronger sides. You no longer see that aggressive, organised and hungry team we so admired.
"They dominated for 10 years, imposing a style of play that was at times truly marvellous. They gave a football lesson to the whole world.
"But now they've hit a brick wall and even Leo Messi can't skip past his rivals any more because the whole machinery of the team is broken down."
No team has previously overturned a four-goal deficit from the first leg, and Sacchi has said he cannot see Luis Enrique's side turning the tie around.
"I always say that to succeed you require, in order of importance, a club, good football and the players," he added.
"Without an idea of what football to play, the individuals will get you nowhere.
"To come back from 4-0 you need a miracle."