Updated

As long as Andres Iniesta and Gerard Pique get healthy again, Barcelona fans should have nothing to worry about.

The 3-1 loss at Manchester City on Tuesday showed that for all the scoring prowess of Lionel Messi, Neymar and Luis Suarez, Barcelona's star forwards can be left with heads hanging when the team's makeshift defense and midfield buckle under pressure.

And pressure is what former Barcelona coach Pep Guardiola ordered City to apply in massive doses, especially in a second half when they broke the steely control the Spanish champions normally maintain even against the biggest opponents.

Barcelona was missing the injured Iniesta, Pique and first-choice left back Jordi Alba. For Barcelona's faithful, that means one bad match shouldn't be a cause of major concern just because three of Barcelona's backups didn't perform as well as its undisputed starters.

Just look at the result of their first meeting two weeks ago, when Messi scored a hat trick in a 4-0 rout. All three started that match, even though Pique and Alba had to be substituted because of injury.

But the loss at City does point out where coach Luis Enrique needs to work with the team's younger players and newcomers. That, or perhaps relent on the club's now ingrained — and ingrained it was by Guardiola — insistence on using short passes to work the ball forward even when under intense pressure from opposing defenses.

"We played 40 excellent minutes with many scoring chances and just in that moment we make a key mistake," Luis Enrique said. "We had five bad minutes and in the second half we accumulated an infinite number of passing errors. (The loss) was the result of our rival's pressure and our mistakes."

Sometimes a game does seem to swing on one single pass.

Messi had put Barcelona on its way to another victory with a goal from a counterattack led by Neymar. Later, Neymar and Suarez both went close to adding more goals.

But a pass from Sergi Roberto that went astray was pounced on by City forward Sergio Aguero, sparking an elegant series of one-touch passes that were reminiscent of Guardiola's best Barcelona sides. The play was completed by Ilkay Gundogan for the equalizer in the 39th minute.

It was all City the rest of the way, with Kevin de Bruyne knocking in a free kick before Gundogan finished off another quick buildup.

Guardiola knows Barcelona better than any rival, and it showed. City made goalkeeper Marc-Andre ter Stegen pass short by covering his down-field options, and then swarmed in numbers.

Barcelona won the possession battle with 60 percent of the ball and basically doubled City's passes (591 attempts to City's 315). But most of the action was inside its own half, when every sideways pass was another chance City had to spring its trap. Guardiola's willingness to renounce the ball worked: City produced 13 shots to Barcelona's eight.

Guardiola said he asked De Bruyne to specifically attack Roberto, who had his worst match after a promising start to the season in his new position of right back.

"We wanted to go one-on-one against Sergi Roberto," Guardiola said. "In the second half we were more compact, pressured higher up the pitch and moved in unison. If we had had better finishing we could have put the game away earlier."

Offseason signings Lucas Digne and Andre Gomes didn't have good showings in place of Alba and Iniesta, either. Digne provided none of Alba's pace and struggled to keep up with Raheem Sterling, while Gomes hit the crossbar with a clear chance to make it 2-2.

The biggest victim of the night, surprisingly, was Sergio Busquets. The Spain holding midfielder, usually so unflappable, relinquished several balls. He was missing his outlets to Iniesta and Pique, who often starts Barcelona's attacks from the back.

"We knew it would be a difficult match and that the team that pressured better and recovered more balls would be the one that won," Busquets said. "During the season there are matches like this one."

According to Aguero, who is a friend of Messi and teammate on the Argentina national side, the Barcelona leader understandably did not leave Etihad Stadium pleased.

"Whenever you lose you're not happy," Aguero said about Messi. "Leo wasn't in the mood and I respect that."

Iniesta will be sidelined for another month with ligament damage in his right knee. A right ankle sprain will keep Pique out for another week, while Alba is expected back soon from a muscle pull.

Once they recover, Barcelona should be its old dominant self.

In the meantime, though, Barcelona faces a tough match at Sevilla in the Spanish league on Sunday. Sevilla coach Jorge Sampaoli surely will have taken note of the flaws that City exploited and try to do likewise.