This isn't Conte's fault. ACL tears rarely come out of nowhere. He has probably been picking up minor injuries or was just tired. It's unfortunate, but I don't quite see how you can blame a manager for it.
Please. His age is a downside. 29 is not young for such an injury, but he'll be fine. When Del Piero got injured in 1998 it could end a player's career. Today most, not all but most, are back to exactly where they were before the injury after rehab.
This isn't Conte's fault. ACL tears rarely come out of nowhere. He has probably been picking up minor injuries or was just tired. It's unfortunate, but I don't quite see how you can blame a manager for it.