The Gunners have confirmed the transfer of the 23-year-old from Borussia Monchengladbach for a fee believed to be in the region of £30million.
Djourou, who will line up alongside Xhaka for the Swiss national team at Euro2016, told Mirror Sport that Xhaka has 'magic' in his feet and possesses similar attributes to Juventus icon and current New York City FC star Pirlo.
"Granit is a great ball player. The guy has a magical left foot," said Hamburg defender Djourou.
"He can ping the ball all over the place. He is a strong tackler - he is very hard going into tackles - and overall he is a very, very, very good player.
"He can see a pass. He can tackle, he can assist. I would say, if I am being honest, there is a little bit of a Pirlo about him, just in terms of the precision that he plays the ball with. Granit can play those types of ball.
"He can come and get the ball and ping it 40 yards onto your feet. He is that kind of player, but with more physicality to his game.
"It is hard to give a perfect description but I would say he has a bit of Pirlo about him."