Barcelona coach Luis Enrique hopes his La Liga champions will learn the lessons from their shock 4-1 defeat to Celta Vigo on Wednesday.
The holders saw their 100 per cent start to their title defence come undone at Balaidos as Iago Aspas scored twice alongside further goals from Nolito and John Guidetti.
Neymar was on target 10 minutes from time for the Catalans but it mattered little for Luis Enrique's side, who were fully punished for an out-of-sorts display, especially at the back.
"I'm not happy to lose 4-1. I'll evaluate and analyse it but it's a test to show how difficult it can be," the Barca boss told reporters.
"All that remains is to congratulate Celta. They played a very complete game, in terms of effectiveness and their football.
"We suffered a lot in the individual battles - the first goal for Nolito went in the top corner but the second was our mistake.
"This result will be useful to tell us that it costs a lot to win - I prefer it when a team wins like Celta did, playing well. They're one of the more attractive [teams].
"We already knew if we committed mistakes we were going to be made to pay for them."
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