That's the only justification for O'Nien I can see, if he is being eyed as someone who can come on for Grimes to see out games and manage his minutes, while also being able to play CB.
I don't get the concerns about squad spaces. We have a small squad. Who's taking them up? We could easily cut the likes of Bell, Andrews, one of Bidwell/Brau if we need to make spaces.
So what's the state of play then
Official: Min-Hyeok
All but official: Esse
ITKs claim in talks: O'Nien, Wilson
Rumours: Neil
Suggestions: Amass, Castledine
Anything else?