Cazorla has revived his career with this season's move to Villarreal.
And Szczesny told Foot Truck: "Cazorla? After the first training session we applauded Arsène Wenger for getting Santi.
"Small, slow, but one of the best soccer players I have ever played with. An incredible winning mentality and technique.
"When you played with him, you thought: 'Oh my God , he's so good'."