He's just playing his usual ultra deep role that he's played for pretty much the entire season under Sarri. His role is to pretty much just do the basic stuff and distribute, he's not expected to be some creative dynamo.
Just a bizarre way to use him really
Sarri is a bit odd
He hasn't given Loftus-Cheek much of a chance either, and he's played far better than a lot of the regulars when he's been given a chance. From what I've seen anyway