Captain Vincent Kompany felt Manchester City could hold their heads high after bowing out of the Champions League in Barcelona.
City failed in their bid to overturn a first-leg deficit as they were beaten 2-1 at the Nou Camp to go down 4-1 on aggregate in the last-16 tie.
As with the first match in Manchester, Lionel Messi and Dani Alves scored the Barca goals and City had a man sent off, this time Pablo Zabaleta.
For a spell when the score was still 0-0 early in the second half, City put the Spanish champions under considerable pressure but they could not find the net.
Kompany told Sky Sports: "I think I speak for the team in saying we've got nothing left in the tank.
"We gave everything. A few times we could have scored, and obviously that would have changed the game.
"Going for a second time down to 10 men after it was a clear penalty - it's not easy conditions to come and play against a strong team.
"Over the course of two games, whenever there was 11 players (against 11) there wasn't much between the two teams."
Messi put Barca ahead after 67 minutes and City's hopes of a comeback grew tougher when Zabaleta was dismissed for protesting about the decision to deny Edin Dzeko a penalty.
Zabaleta said: "It was very clear. I think (Gerard) Pique was behind and made the tackle on Edin Dzeko and the referee was only two metres away from that.
"I don't know why I was sent off. I went to him to talk to him in a good way. I was a little bit angry to him because he didn't give a penalty but I have always been very respectful to him.
"I am frustrated. I think it was a shocking decision."
The result came just three days after City were eliminated from the FA Cup by Championship side Wigan.
They can now focus solely on their Barclays Premier League title bid.
Kompany said: "If anything, it should give us motivation.
"The way we played against Wigan, the performance today was completely different.
"Only the winners get remembered, but it's only the third year ever for Manchester City in the Champions League.
"I'm looking at this and I don't see why next year we should fear anyone."
Assistant boss Ruben Cousillas, who called the shots in the technical area with manager Manuel Pellegrini serving a touchline ban, also promised City would be back.
It was the first time City had reached the last 16 and Pellegrini's project, which has already yielded the Capital One Cup, is still in its infancy.
Cousillas said: "We played a very good game against a very good team.
"They also had their chances, but we showed our quality. It was a very difficult to do that with 10 men against a team like Barcelona, but we go home happy with the performance.
"Our project is just starting, we have been here eight months and just won our first silverware.
"Up to last weekend, we were the only team chasing four trophies, which is not easy to do.
"We are out of two, but are still very much alive in the PL. The team is recovering and have been through some low times, but we are alive and we will fight for the title."
The downside for City was the loss of top scorer Sergio Aguero at half-time with another injury.
The Argentinian will have a hamstring scan when back in Manchester.
Aguero said: "I felt a twinge in the leg early on after a challenge with Messi.
"I carried on with it for the rest of the half but at half-time we decided not to risk it."
Barcelona coach Gerardo Martino, who has been under pressure over perceived indifferent form, felt the victory would give his team much encouragement.
Martino said: "You have to remember what was said when the draw was made - that we were going to suffer a lot - and we won 4-1 and won both matches.
"City are very good individually and collectively. If we are capable of playing both matches the way we did against a team of their quality then we can face any of the winners in the quarter-finals."