Recent news said Chiellini could miss 3 months due to calf injury, while as far as I know Juve "only" have Careces and Marrone for the back up. Either we switch to 4-3-3 more often or another CB in window transfer.
good news: Careces and Marrone will have more chances to play
bad news: in case another CB get injured, Juve will be left with only one back up for CB position which is worrying. In addition, Marrone is not a natural CB