I've been critical of him time and time again in this thread. And I agree that Sheffield game was not among his best. I agree that his passing is not top level.
But looking at the current state of the squad, selling him would be awful idea. Who do we play in CB then? Jan will leave, god I hope Foyth as well (how fucking long do we play around with him? just not good enough), Toby is past his prime, Tanganga seems promising but right now I would say that he is "a sure thing" quite yet.
Opposed to some others, I can recall some games where Dav was good. Though as someone mentioned- mostly in games we were on the backfoot most of the time.
I am not saying that some specific situations / decisions were because of that, but more general reason why every single defensive player has looked s*it at times is that our midfield don't provide enough cover for defense. Get in a strong and good DM. I don't think it was just random that people started to notice Jan-Toby flaws more after changes in CM department either.
So to me it would seem way more logical to ship out Jan and Foyth; give Tanganga some more time to settle in and prove himself, bring in one new and good CB. And Tanganga proves himsef further + new acquizition is success - then move him on in next summer. We cannot do everything with one go (e.g sell Rose, Jan, Foyth, Sanchez, KWP, Aurier and bring in 2 new fullbacks + 2 new CBs) - thats not how team dynamics work.