Yes, lets give Del Piero a high rating because he looked sad and showed that he cares.
He was terrible yesterday, just like most of our players, excluding Manninger, and maybe Canna and Melo. Even 5.00 will be too much for the way he played. He never thought about passing, couldn't keep the ball and tried to dribble through 3 players all the time, which didn't work at all. Solid 15 minutes followed by disastrous 50-60 minutes. Rightfully subbed.
Being sad and playing out of position isn't a reason to give him a passing rating. If yesterday's match was an exam, he'd have failed badly.