What I think is Lippi is reasonable to some extent.
Firstly, Juv has been leading Milan for 8 points. That is not a small gap.
Even if they lose this game to Milan, they are still 5 points lead.
That's not a small amount as well. Therefore, to Juv it is a normal game
and to Milan it is a die-is-out game.
Secondly, don't forget European Champions League is incoming. Although Piero
is ready, Lippi would not like to take the risk of presenting him in the starting
time. Lippi surely know that this is an significant match for Milan and they will
go all out to grab a win at any price. The least thing he'd like to see is that
Piero will be injured again. To this point, Lippi still kept some reservation for
this match. And this is verified by the whole match. Both sides kicked heavily.
More than 2 yellow cards issued.
Last not the least, I'm sorry to hear that you are a Juv fan. But do not be heart-broken.
Juv still have better opportunity and do not forget Inter Milan. From the match schedule,
they are the most suitable candidate for champion of Series A, believe it or not.