The Polish goalkeeper is enjoying his first week of training with Barca.
He said, "He has been impressive for me. After seeing him on TV I expected him to be a modern type of defender, nice on the ball, but green.
"When you see him in person, he is actually not green at all and makes very good decisions. Of course he is good on the ball because his technical quality is very high, but his defensive qualities are actually very, very high.
"I am looking forward to partnering him. He impressed me a lot. The defenders too."
Szczesny added: "Can I say 'no' to Barça ?' And the answer is that you can't say 'no'. If you say 'no' to Barça, it's because you don't have the b***s or the courage to take on a challenge like this. You don't have the courage for it."