"Who impressed me the most during these first few days of training? That's too easy, it's Pirlo," Marchisio told the official Juventus website.
"I play with him for the Nazionale and it's a great pleasure to have him as my teammate here at Juve as well.
"He is able to give us a huge hand."
There were many reports that Marchisio would be moving on this summer, including a possible switch to Milan.
"I am in good shape and finally managed to relax over the summer with my family. I'm raring to go."