Our problem has been using Dier as the senior CB too often.
I think the more daming thing of him as a CB is that Mourinho couldnt get a tune out of him.
Im no great fan of Mourinho or how he operates, but I think its fair to say he knows how to work with defenders and how to make them look good.
And Dier really never looked good under him at all, if not under him - then who else stands a chance?
I quite liked under Poch having Dier in midfield, slipping into defence - gave us a real dynamism in our structure that worked brilliantly at times.
But I dont see Dier as solely a CB, which apparently he does, so will be interesting to see what the new management make of that one. Could be time he moved on.