Empty seats have marked recent Emirates Stadium matches as supporters demonstrate dissatisfaction with a campaign that appears likely to end without qualification for the Champions League for a second successive season.
Winning the Europa League is the Gunners' last realistic hope of returning to the competition next term and they can strengthen those chances with a strong showing in the first leg of the quarter-finals on Thursday.
Club great Ian Wright has commended Arsenal fans for the "positive step" of staying away from matches and Wenger accepts slumping attendances are a worrying trend, albeit one he believes will soon end.
"I'm always concerned when our stadium is not completely full," the Frenchman told reporters on Wednesday.
"But I don't think that will be a problem tomorrow. Our concern is the performance and the crowd will be behind us.
"I think when something is at stake the crowd is always behind us."
Arsenal have been boosted by the return to fitness of Alexandre Lacazette as they attempt to reach the final four of a European competition for the first time since 2008-09.
"Basically we have everybody available, I think," he said.
2 - CSKA Moscow are one of just five teams that Arsene Wenger has faced more than once with Arsenal and failed to win against (also Fiorentina, PAOK Salonika, PSG and Port Vale). Bogey. pic.twitter.com/i2iKj6IzfD— OptaJoe (@OptaJoe) March 16, 2018
"Lacazette is ready to start. I have not decided if he will start or not but he is available and ready to start."
Petr Cech missed the win against Stoke but is available, although David Ospina typically starts for Arsenal in cup competitions.