Barzagli was subbed for the right back on the 83rd minute in a game we were wining, against a team we were better than, at home.
It didn't work, but that is a reasonable sub. This is not the reason we lost, its an overreaction. It was bad luck, complacency at the end, Szczesny on the second goal, and of course not having scored more from the many chances we had.