Quaq lost half of the season due to injury, Aquilani didnt (neither Sorensen), so he is less consistent in my books.
Quaq was much more impressive in the first part of the season (which i lost since i was in the army then), but you cant ignore that he has lost half of the season.
Pirlo also lost quite a lot of form, as he had minimal contribution in the past season. He has a steady decline in appearance and work rate, considering his age, its impossible to rejuvenate his form now. If we expect him to be a starter, we must either be ready for huge compromises in quality, or be ready to replace him with a player of equivalent value.
As we are about to sell Melo and Sissoko, this player would be Pazienza and it is really really doubtful such a limited player will be able to curry the mantle of Juve starter for 35-50% of the season...