"I will not take a crazy gamble," Wenger said of his compatriot Nasri, who he admitted is "physically ready" after a two-week layoff with a hamstring injury.
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"He has worked very hard in the last week... just there is a risk to have a setback," Wenger added on the club's website before saying Nasri would have tests on Monday and Tuesday.
"Who isn't desperate to play? But there is another game in three weeks. We also have Leyton Orient, the Carling Cup Final, we have so many games coming up it is important not to be stupid."
In last year's Champions League quarter-final Arsenal clung on for a 2-2 draw in London against the Spanish champions but were torn apart 4-1 at the Nou Camp.
"Here (at Emirates Stadium) we will try to play to our strengths," Wenger said. "We will try to attack the other team."
