I think you're looking it the wrong way.
Would you prefer Pjaca to start and gets substituted at half time for not making an impact? That could hurt his confidence.
Mandzukic is working his ass off out there but he is in physical decline (though still a machine), and cuadrado is hit and miss.. he will get minutes, but we're playing well and it's money time, so I think Allegri is spot on with him.