From goal.com
"..However, Thiago Silva is to defending what Lionel Messi is to attacking, the kind of absolute excellence that is simply not within the reach of any other player in the game. The centre-back is, in a word, irreplaceable. Losing him means Milan will have to resign themselves to the fact that no matter what they do during the remainder of the summer, they will have weakened their team, and given away the man they wanted to remain as their cornerstone in the most radical overhaul in the club's history.
The time to say goodbye, it seems, is now close at hand. Thiago Silva was Milan's 'Capitan Futuro', their leader-in-waiting, the new symbol of the club. However, it seems the flag is set to be lowered before the ship has even set sail."