He's a good squad player that can fill in a number of positions if needed but shouldn't be a starter when we have a fit squad.I actually don't think the tactics exposed him. Sitting deep where he can get his head in the way or direct lads around him is where he's at his best. Play high up the pitch and he gets exposed. Look at the Leicester game away last season. 1 v 1s he got done on two of them for goals I think. There was one just before half time that was horrendous defending. Look at the Man U game at home. Rashford got him 1 v 1 and destroyed him. He just didn't have either the pace or the defensive sense to cope. You can't play a high line with Dier.
I'm not a hater by the way. I think he's been a good servant to the club and I love his attitude and what I know of him as a person. But his involvement now should be limited IMO.