Based on this season alone, no player has done anything of note. And besides, in their defense, both players have been injured for large parts of the season. Their value still exists in the dressing room, even if people feel it's diminished on the pitch.
Chiellini and Buffon have been avergae, by their standards, nowhere near the Shocking form of the rest of the squad. Both have been injured, admittedly for less time than Camo, but no less than Trez, in Buffon's case. Camo has done next to nothing when played, and caused more harm than good. His Good is exceptionally Good, but his bad is exceptionally bad...as in cards and giving away free kicks for nothing more than puerile viciousness. As for Trez, he is a player whose whole game is based on match sharpness. Without that his ability to ghost into goalscoring positions is hugely compromised. Trez has more of an excuse for less than average form, than Camo...He is old now, but I would be happy if he stayed. But not Camo...he needs to go. Whilst we can still get something for him. Lose his wage, grab a few million, maybe anywhere between 1 and 5m, then add that money to buying a top class winger, and maybe rodriguez also...we will have those two and Iago and Giovinco for the wings...
As for their value in the squad. I doubt I am the only one who sees Camo as more a liability than an asset, a player who is not at all happy...Trez? well he has done amazing things for the club. but not for two seasons now...mainly due to injury. If he wanted to go home to France, i wish him well and thank him as much as revere him, for all he has given to our cause...but NO, i dont think they haVE an large effect on morale in the dressing room.