Mexes was badly at fault for the first goal for giving the corner away & then Mexes totally lost Toni on the corner & Zapata should have done better on the second goal.
I want to though make a comment on the performance of Abate in this game, he just at no stage in the whole 90 minutes did hardly any defensive work at all. Yes Zapata had a poor game, yes Mexes had a poor game, yes Constant was not good, but they where trying to defend & doing their best on a day when they played badly, but the performance & lack of defending from Abate was shocking.
Abate defended & played well at PSV, but he played like a right winger yesterday when the team needed help at the back & he almost looked like I did well in the week defending today does not matter. Niang was poor, but he did more defensive work than Abate & he's a forward player.
If I was coach I would have have destroyed Abate for what was a totally shocking defensive performance. When Verona scored the winner Abate was further forward than all Milan's front three which says it all when he should have been 50 yards back helping Zapata defend the situation.