It's all very very odd. It's striking me as not too dissimilar to a Chelsea punt purchase (Michael Hector etc) with a view to profit down the line, rather than a long-term strategy. I don't really like the club looking at player's in that vein, though I may be being a touch cynical.
If it was more 'bring him in and bed him in slowly to see what he can do' then fair enough, but the players we've done this with before have, with the exception of Robertson, been very, very expensive players we were always going to utilise at some stage.
Robertson is the one to look at really here for him, massively under used and practically written off as a pointless signing by some, before seizing his chance and massively emerging. It does strike me as odd he's not had any minutes whatsoever, considering last season he was in the Championship and played against Premier League opposition, whereas someone like Phillips and Williams were in second division and non-league (with young Rhys especially struggling).