Juventus manager Massimiliano Allegri (AFP)
Juve supporters made their feelings heard loud and clear on Wednesday night, a barrage of whistles and boos which greeted the 2-1 loss the culmination of months of discontent with the man who guided them to five Serie A titles.
Zero points from two games has left Juve floundering in Group H, six behind both Benfica and leaders Paris Saint-Germain, and the message "Allegri Out" is reaching a crescendo among fans on social media.
On Thursday the Gazzetta Dello Sport described Juve's disjointed performance as "the end of an era" for Allegri, the coach having "used up all the credit accumulated when winning all those trophies and getting to Champions League finals".
Allegri, 55, returned to Juve last summer hoping to reignite Italy's biggest club after Maurizio Sarri and Andrea Pirlo both turned out to be inadequate replacements for the man who in his first spell made them a force in Europe.
However the comeback has not gone according to plan, with Juve finishing 16 points behind champions AC Milan last term and starting this campaign poorly.
Juve have had huge problems with injuries in the early part of the season and Allegri was without the likes of Paul Pogba, Manuel Locatelli and Federico Chiesa, only being able to count on Angel Di Maria as a second-half substitute.
But the available players are better than two wins from their opening eight games in Italy and Europe and above all capable of performances of a higher standard than seen so far.
They have only played well in bursts, dropping out of games midway or taking ages to get going, and Wednesday night was a case in point.
- Bonucci 'worried' -
An early flurry led to new signing Arkadiusz Milik -- one of the few bright spots -- heading in a fourth minute opener.
However, from there Juve offered little and Benfica grew into the game, first hitting the post through Rafa Silva before former Inter Milan man Joao Pedro levelled from the penalty spot just before half-time.
After David Neres put the away side ahead early in the second half Juve collapsed and would have conceded more had Mattia Perin and captain Leonardo Bonucci not been at their best to stop a clutch of efforts as Benfica threatened to run riot.
Afterwards Allegri insisted he "didn't feel at risk" of losing his job but results have not improved since his return.
The stale football is in stark contrast to the vibrant likes of AC Milan and Napoli, who lead Serie A and their respective Champions League groups.
Captain Leonardo Bonucci was close to tears when he and the rest of his teammates approached the Juve fans at the end of the match and were assailed with insults.
He looked lost for answers as to what was going wrong.
"We're in a period in which we struggle to do anything," said Bonucci.
"I'm worried, we can't hide it, because we vanish from games too often, whether it's a mental or physical problem I don't know but that's what worries me."
The depth of antipathy from supporters -- some of whom are also in conflict with the club over what they consider high ticket prices -- was highlighted by empty seats in the stands for a crucial match in the group.
The defeat has severely damaged their chances of making it through to the knockout stages.
Maccabi Haifa showed in the way they attacked PSG on Wednesday they won't be rolled over easily, and if Juve want to get out of the Group they will likely need to win both their upcoming matches with the Israelis.
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