Luis Aragones has warned Spain to sharpen up their defending ahead of the European Championship.
The Spain coach was unhappy with the goal his team conceded in Saturday's 2-1 friendly win at home to Peru.
A poor clearance from Carlos Marchena allowed Peru to equalise and Aragones admits similar errors at Euro 2008 will prove costly.
"Giving a goal away like that could cost us very dearly in Euro 2008," said Aragones.
"I didn't like the way we conceded that goal. Sometimes you just have to boot the ball away and not try and play it out of defence.
"In the big tournaments it's vital to keep a clean sheet."
Have to improve
Marchena could lose his place in the Spain team for Wednesday's friendly with the USA to Raul Albiol, but he has been given the backing of his fellow Valencia defender.
Albiol said: "You can't blame Marchena. These things happen in football.
"It's better for something like this to happen rather than a failure in positioning which is much harder to correct.
"It's clear we have to improve in attack and defence, but the most important thing is we keep working to prepare for Wednesday. Another win would set us up nicely for the opening (Group D) game against Russia."