The Gunners could only draw 0-0 against former boss Unai Emery's side on Thursday night as they missed out on a coveted Europa League final place.
After an inconsistent Premier League campaign, Arsenal look like facing a first season without European football in 25 years.
"We have no time because we have a game on Sunday," he replied when asked whether the team can harness the pain they feel.
“We had a training session on Friday and it had to be when you leave the training ground, most of it has to be out of the system.
“I think you have to leave some of it in some of your system, and use some of it in the right way as an energy driver in the game on Sunday."