Chiellini also was responsible for 2 or 3 of the goals we conceded in the early part of the season, I'm thinking the Hellas, Chievo, etc. games. He has improved since then and was very solid in the last few weeks, but those mistakes still drag him down in my books. I'd maybe rank him 5th best CB in Serie A, after Benatia, Barzagli, Campagnero and Lucarelli (Parma, has done great considering his team members).
If he continues his current form, he might well be in my team of the season come may, but so far, no.