With a 100m to burn there will be a few who can be made available.
What is Pogba's current level? Can you say with certainty that Jose wants to play him as a box to box midfielder, or does he want him as the more attacking midfielder in three?
Also, there are different ways to skin a cat.You don't always get the same type of player with the same abilities; you adjust. You get Carrick for Keane and make it work.
I don't think the club is going to pay 100m for another midfielder. Pogba is a top class player already, and he has the potential to be world class very soon - however, he is also unique in the sense that he is the type of player that can be the face of the club marketing wise.