Coach Xavi Hernandez promised to return Barcelona to the summit of European football after they crashed out of the Champions League with a 3-0 defeat at Bayern Munich.
Five-time European champions Barca were eliminated in the group stages for the first time in 21 years in a miserable night for the coach and his shell-shocked players.
Goals by Thomas Muller and Leroy Sane gave Bayern a 2-0 half-time cushion in falling snow at the Allianz Arena, which was without spectators due to high numbers of Covid cases in Bavaria.
Teenager Jamal Musiala grabbed Bayern's third after the break to seal Barcelona's fate.
"I'm angry. I don't like that this is our reality now. We start a new era from here - to work hard and get back in the Champions League," said Xavi.
Midfielder Sergio Busquets, speaking to DAZN, said: "We feel very bad right now. We're in a tough, difficult situation. We got ourselves into this mess and it hurts a lot."
Bayern, who also beat Barca 3-0 at the Camp Nou when the sides met in September, had already qualified for the knockout stages as Group E winners and didn't need the victory.
They now join Liverpool and Ajax with a perfect six victories from six games in the group stage.
It was almost eight years to the day since Bayern lost a home Champions League game in the group phase and the Bundesliga leaders were in no mood to be generous.
Xavi, 41, who took charge of struggling Barcelona four weeks ago, has now suffered back-to-back defeats after his first loss as head coach against Real Betis last weekend.
"We start from scratch. Unfortunately, we are in the Europa League, which is not the place for us," he said,
"We will work hard to put Barcelona back in the right place. We have many things to correct. We need to win the Europa League and recover the points in the Spanish league.
"We have had some injuries, maybe we can sign some more players, but we start from zero."
Bayern were not even at full strength with Joshua Kimmich quarantining after a positive Covid test and Leon Goretzka injured.
Barcelona made a bright start but faded after losing Jordi Alba to injury with half an hour gone, just before Muller headed Bayern into the lead.
Robert Lewandowski found space on the left of the box and flicked a pass to Muller who claimed his 50th Champions League goal when his header looped beyond the reach of Barcelona goalkeeper Marc-Andre ter Stegen.
Things went from bad to worse for Barca when Sane hit the net with a powerful long-range shot that deceived Ter Stegen.
Sane should have put the result beyond doubt when Bayern attacked just after the break.
Instead of tapping the ball into the empty net, he poked the ball into Ter Stegen's grateful arms.
Alphonso Davies, who also ran Barcelona ragged in Bayern's historic 8-2 drubbing in the 2020 quarter-finals, again caused havoc down the left flank.
The quicksilver Canadian created Bayern's third when he pulled the ball back for Musiala to tap home from close range on 62 minutes.
With 20 minutes left and the contest effectively over, Bayern coach Julian Nagelsmann started taking off first-choice players.
First to go were wingers Davies and Kingsley Coman.
Then followed star striker Lewandowski and centre-back Niklas Suele, yet still Barcelona could not threaten Manuel Neuer in the Bayern goal.
After the final whistle, Muller backed Xavi to turn Barcelona around.
"When you look at the (Barcelona) team, they are good players, they have everything they need," said Muller.
"We know things aren't going so well behind the scenes and I had the feeling they couldn't find the intensity they needed, which helped our cause."