Sound like he's identified the problem. Our main problem for the last seasons has always been a lack of work rate, our players are just not ready to put in the work required to be a succesfull team. Off the ball movement is minimal, our players are usually just standing still while the passing lanes to them is covered by opposition players.
Yesterday we made some big mistakes when trying to build play from the back and the passers are made the main scapegoats for it. I,m not saying De Gea, Maguire, Eriksen, etc didn't make mistakes when on the ball but our wide players and midfielders didn't do anything to make themselfs available for a pass. Dalot and Shaw went wide and just stod there while the passing lane to them was covered, Fred was standing still next to a Brentford player in the middle, waiting for someone else to take the responsibility and Bruno, Sancho and Rashford where usually nowhere to be seen. If we want to build play from the back the most important thing is that the players not on the ball are constantly moving to make themselfs available for the pass, yesterday we saw nothing of that.