The midfielder had been linked with Manchester United as doubts over his future persisted.
“Juventus have never thought about selling Marchisio,” Marotta told calciomercato.com. “Not now, not ever.
“In September 2012 the club extended his contract until June 30, 2016, adjusting his salary too.
“I think this is the clearest demonstration of how important Marchisio is for Juventus.”