He is a decent centre back no better no worse. I would ideally like to see us buy 2 new first choice centre backs in the summer and keep Mori, Keane and Holgate as back up. If we only get one centre back it wouldn't be the end of the world if the 3 of them were competing to partner the new...
I would definitely like to see him and Keane given an opportunity to play together until the end of the season. Holgate on the bench as cover. We will still need at least one more in the summer but if they show promise at least it will be a start.
Hopefully Mori back on the bench and with Baines back at left back as well maybe get some balance in the team. He needs to be getting an hour in today hopefully and no reaction. If he's got I would play him alongside Keane or Holgate. He will improve the team but is probably not the long term...
If we get a decent left sides CB in the window he won't be missed as much. Otherwise I think with Williams being so bad we'll end up remembering him as though he was as good as a Baresi/Maldini hybrid.