I don't consider Bonucci and Marchisio our best players, so I'm not really sure what that means. I guess if you want to query the forum for positive hits then yes Marchisio is the best player in the world.
Pogba was outstanding for 2 months before his injury, and average before newyear
Vidal was average in everything, but got back to his excellent defensive game at the end of the season
Pirlo was a huge defensive risk and very poor offensively, but managed clutch freekicks several times
Morata grew into the season, while Llorente never started it
