Just my perception. I note whoever you pair with Dier, there is too much to and fro passing between them, barely finding a pass forward. In the absence of Toby, Dier appears to be the designated hoofer... and he is poor. Rodon inevitably (being younger and newbie) is still quite rigid and seeing how Jose slates mistakes, he is playing safe. But the pairing with Dier irritates me. Rodon has a good physique and height and will mature to be quite imposing.
Dier's heading imo is very poor, like Sanchez, is very random in to no man's land. Dier doesn't read the corners very well. Not the first time he was caught by the flight and Goldrick simply our-muscled Davis for the header.
Final rant is, and I have watched it time and time again to comment, Dier takes too many pauses before passing the ball. Partly due to no outlet but mostly he's looking for the clever long ball which he invariable executes poorly.
Pretty obvious I am not a fan of Dier!!. I think playing at DM over several years, he's like a new signing still learning.