The coach of the Bavarian giants confessed his team was fortunate to reach the Champions League quarterfinals and openly disapproved of its below-par performance
Despite the loss the Bavarian giants progressed to the quarterfinals on the away goals rule and only suffered a bruised ego rather than elimination, but the coach admitted things did not go as planned.
"I think altogether we have to be critical of our performance today. At the end, we did get away with a black eye, however," Heynckes told ZDF.
"That early goal made us lose our concept and rhythm a bit. I would not say we were surprised, but we were not really up to it, especially during the first half.
"We never played as calm, as we usually do. This game should be an instructive example for us: You have never reached the next round, until the match is played."
Bayern chairman Karl-Heinz Rummenigge said his side was fortunate to have qualified on the back of its first-leg performance and added the absences of Bastian Schweinsteiger and Franck Ribery were certainly felt.
"It was a difficult match tonight and we lost 2-0. We are lucky we won the first leg and that makes us go through," he said.
"This might me a warning for us in the Champions League. The stakes are high and you have to be humble."
"It was definitive noticeable [that Schweinsteiger and Ribery were missing], since our game was not as well-structured as it usually is."
Arjen Robben also voiced his opinion that die Roten underperformed and echoed Rummenigge's sentiments that they must heed the warning from the defeat.
He added: "We shouldn't have allowed this to happen. Arsenal had nothing to lose. We should have put up more of a fight. Maybe this was a wake-up call for us."