I have high hopes for Semedo this year myself, but talking about what has actually happened, rather than wishful thinking...
I certainly don't think Doc was idle under Nuno. He actually physically pulled himself together and had a couple of top flight seasons playing at the very limit of his ability and contributed massively to our success. He gets next to no credit for that either, which is a shame.
Semedo struggled with defending, crossing has been patchy too, he cost considerably more than we sold Doc for, and the team performed significantly worse with him in it.
In fact, the whole 'evolution' from that wingback style Doc was a fairly big part of was a giant clusterfuck that precipitated the departure of the manager and the current unsettling flux we find ourselves in. It's hardly been a particularly successful swap for us so far!