Remarkably, Barcelona managed to score just once in a dizzying performance in which they created 23 chances on goal, with Ivan Rakitic deftly beating Hart after 31 minutes.

Messi was at his magical best and almost untouchable, and over the two legs of the last-16 tie, City were flattered by an aggregate 3-1 scoreline.

The outcome might have been different had Marc-Andre ter Stegen not saved a second-half penalty from Sergio Aguero but Barcelona’s superiority could not be doubted.

Barca had 11 shots on target. Ten of them were saved by Hart while Luis Suarez hit the woodwork twice.

The match had been billed as critical for Pellegrini, with his position under heavy scrutiny after a dispiriting spell that has all but ended hopes of retaining the Barclays Premier League title.

But there is little any tactician could have done to subdue Barca in such rampant mood.

Hart said: “It’s always going to be the same at City, for all the players. We appreciate that if we don’t win everyone will be speculated about. You have to be strong inside.

“We back our manager. He is a great manager and brought us two trophies last year. Now we have nine games to win, and that’s what we hope to do.”

It was the second successive year City had gone out to Barcelona at the last-16 stage. Hart acknowledged the excellence of the opposition but could not hide his disappointment.

The England number one said: “It’s disappointing – we gave ourselves a chance and didn’t take it.

“We’ve gone out to a magnificent side but that’s the second time in two years, which is disappointing for us.

“I had a lot to do, but I wanted it to count. I said that after the first leg, and it hasn’t.

“Make no bones about it, Barcelona were the better team in both legs, but we hung on in there, defended and made saves, and made tackles, but then didn’t take our chance to get back into it.

“We have to learn to take our chances. Sometimes in Europe you won’t be the better team and you have to somehow find a way to win.”

After the game Pellegrini again highlighted the issues of fixture congestion in December and January as well as the club’s restrictions under Financial Fair Play regulations for their lack of progress this term.

But he felt it was “not the correct moment” to analyse such matters and instead tried to point out there should be no shame in losing to such a strong Barcelona team.

He said: “It is not a failure, I don’t see it is a failure. It is a disappointment, but we have reached the last 16 twice.

“We were unlucky to play Barca on both occasions. We took risks and fortunately for us we had Joe, who made very good saves.

“But if we had scored the penalty, maybe it would not have been so quiet for Barcelona in the end.”

The game’s biggest star was Messi, who continued the sensational form that has already seen him score three hat-tricks in 2015 with another masterful display. One of the night’s enduring images will be of the moment he nutmegged James Milner and left the England international on the turf.

“When Messi gets the ball, he just gets away from all the players,” said Pellegrini. “It creates a lot of difficulty for our players, the ball is stuck to his foot.”