After winning the second-leg of their Copa del Rey semifinal at Atletico, the Pole had a dig at the hosts.
A 1-0 win at the Metropolitano saw Barca reach the final 5-4 on aggregate.
Speaking on TVP Sports, Szczesny laughed: "I have not made any crucial stops today. I had to pretend I was doing something!"
Asked if he enjoyed the night, the veteran keeper continued: "Yes, it was good to be there, in a semifinal.
"They launched their best players in the attack, but we were very sure. It was a semifinal and they needed a goal to get to overtime. It is normal for us to back down a bit.
"That doesn't mean we didn't want a second goal and a third. You have to suffer a little, but they did not finish once between the posts. A professional job done."
The former Arsenal and Juventus keeper, added: "Yes, it is without a doubt the most beautiful team I have played on. I cannot deny that it is also the most effective.
"Playing in Barcelona is very interesting. I recommend it to all future Polish players. Work hard, maybe someday you will have a chance like this."