Arsenal midfielder Samir Nasri admits stopping Lionel Messi will be key to defeating Barcelona this week.
Nasri believes shackling Messi is the key to overcoming the best team he has faced.
"It's harder to stop Messi than Xavi or Andres Iniesta because he can make the pass, can dribble, can score. You cannot stop him," he said.
"Even if you follow him for 90 minutes you know something will happen because he has such quality to make the difference.
"Xavi and Iniesta are more players with the pass. But Messi can make the difference alone."
