Dani Alves believes Barcelona's "machines" are capable of producing a stunning turnaround in their Champions League last-16 tie with Paris Saint-Germain.

Luis Enrique's side were thrashed 4-0 in the French capital on Tuesday to leave their hopes of reaching the quarter-finals for a 10th season in a row hanging by a thread.

The insipid nature of Barca's display - and the lack of an away goal - in what was their joint-heaviest defeat in the competition left even Neymar to concede that their chances of overturning the deficit in the second leg at Camp Nou are remote.

But Dani Alves, who lifted the trophy three times in a glittering Barca career, does not consider the task to be hopeless.

"It's very tough to come back, not because Barca can't but because of the quality of their opponents," the Juventus full-back told Sport. "They press, they don't let you play.

"I always want them to do as well as possible. In football, anything can happen. If anyone can produce a comeback, it's the Barca machines."