After the Gunners had failed to capitalise on a series of chances to break the deadlock and had to settle for a 0-0 draw, Cesc Fabregas summed up the mood in the dressing room.
"I think we should go home disappointed after the chances we created (without scoring). We deserved more than we got tonight," the Spanish midfielder told Sky Sports.
Defender William Gallas echoed his team-mate - but still thinks Arsenal can get past the Champions League holders into this season's quarter-finals.
"They played very well and defended well. We had the chances to score but didn't do it," he said.
"They are a big team and tonight they showed what they can do.
"But I think we have the chance to win there. We know it will be very tough - and we have to be ready for a big fight."
Gunners boss Arsene Wenger was also frustrated his team could not convert their many opportunities - but was nonetheless happy at a heartening performance as his players reacted in the right way to their 4-0 FA Cup thumping by Manchester United four days ago.
"We showed maturity and got a clean sheet - which is very positive for the second game," said Wenger.
"We were dominant in the second half but just could not take advantage.
"Overall, I am very happy with the response I got from my team - the quality we have shown was outstanding."
