Roma captain Daniele de Rossi played a crucial role in the second leg

"Historical debacle," announces Mundo Deportivo. "Another ridicule," blasts Sport. "The Fall of Barca's Empire," trumpets Marca. "Without football or fight," laments El Pais.

There is certainly a consensus among the Spanish media: Barcelona got what they deserved in Rome on Tuesday night, suffering elimination from the Champions League at the quarter-final stage for the third consecutive season after an abject performance.

Having a 4-1 first-leg lead overturned by a Roma team 21 points off the pace in Serie A was the last thing Barca expected, and it will take a while for reality to sink in as the Catalan giants come to terms with one of the most shocking results in the club's recent history.

So how on earth did it happen?

'Barca were out for an early-evening stroll'

One word sums up the difference between the two teams on the night: intensity.

Roma were buzzing all over the pitch, flying into challenges, pouncing on loose balls, pressing high up the pitch with fierce aggression to stop Barca's build-up play and getting the ball into dangerous positions as quickly as possible.

Barca, meanwhile, looked half-asleep, as though they were heading out for a gentle early-evening stroll while casually considering their plans for dinner.

In truth, the first few minutes were pretty good for the Spanish team, who had a couple of early chances to take the lead as Sergi Roberto shot straight at home goalkeeper Alisson and Lionel Messi mishit a shot wide.

But that changed in the sixth minute, when a routine long ball through the middle was not dealt with by Jordi Alba or Samuel Umtiti, then Marc-Andre ter Stegen stayed rooted to his line and a surprised Edin Dzeko took full advantage by poking home the opener.

The Roma fans at Stadio Olimpico played their part

From that moment, the complexion of the tie was totally changed as Roma were injected with a major dose of self-belief, while Barca retreated into their shell and appeared to have little plan other than hoping they could hold on.

Roma played as though they were perpetually in fast-forward mode, but Barca were stuck in slow motion, taking an age to deliver their passes and giving the home team far too much time and space to create danger with a barrage of crosses into the box.

To put it simply, Roma wanted it more. True, at times their physical approach overstepped the mark, with Juan Jesus fortunate to only receive a yellow card for a filthy foul on Messi and Fazio lucky to escape a second caution after scything down Andres Iniesta.

But that should not be an excuse for the visitors, whose lacklustre display was startlingly similar to their heavy losses at Paris St-Germain and Juventus in last season's Champions League. Clearly, lessons have not been learned.

Valverde under fire

Barcelona coach Ernesto Valverde did not make a change until the 80th minute

Although Barcelona's players will certainly not escape condemnation for folding so meekly, coach Ernesto Valverde is also facing severe criticism for his handling of the fixture - and the season.

From the early stages it was clear that his gamble to select Sergio Busquets, who has played only an hour of football in the last month after suffering a foot injury against Chelsea, was badly backfiring.

Busquets was being overwhelmed in midfield, unable to exert his usual cool control over possession, and he desperately needed to be supported or replaced. And it is not as though Valverde lacked options.

With Barca being physically dominated, it looked like the ideal game for the introduction of the powerful Paulinho. Or Valverde could have stretched the action and given Roma's defence something to think about by bringing on winger Ousmane Dembele. Perhaps a bit more control and guile in midfield through Denis Suarez or Andre Gomes. Maybe even bolstering the defence by employing Thomas Vermaelen as a third centre-back.

Instead, though, Valverde chose to do nothing at all, refusing to make any substitutions until the 80th minute. His inaction has been very badly received.

Barca running out of gas?

Barcelona look like they do not have enough squad depth

Fortunately for Barca, they have already got the league title wrapped up, holding an 11-point lead over second-placed Atletico Madrid with only seven games remaining.

They will also have the chance to secure a domestic double a week on Saturday, when they face out-of-form Sevilla in the Copa del Rey final in Madrid.

But wrestling European dominance out of Real Madrid's hands was a big priority for Valverde and his players, who can only regard their failure to land the treble as a massive wasted opportunity from a position of great strength. A double would hardly be a bad season, but it could have been so much more.

Perhaps the biggest long-term conclusion will be that the squad's depth needs to be significantly improved.

Valverde probably did not make any substitutions for the simple reason that he did not like his bench options, which also explains why he has not rotated his team much in the past few weeks, leaving Pique, Iniesta, Alba and Luis Suarez looking desperately weary at this key stage of the campaign.

Valverde's squad depth - assuming he rides the current wave of criticism to retain his job - will be automatically strengthened next season by the availability of Philippe Coutinho, who was cup-tied against Roma after representing Liverpool in earlier rounds.

Another big-money signing, Dembele, should also be better integrated, and the anticipated signing of Atletico striker Antoine Griezmann would provide variety in attack.

But it is in midfield where Barca really need to improve, especially if Iniesta accepts an offer to move to China. Paulinho, Gomes and Denis have rarely looked Barca-quality, and Busquets and Rakitic cannot do everything by themselves game after game.

They might be poised to win La Liga by a landslide, but Barca still face some big decisions this summer.