RE: Manchester United's and her defensive deficiency.

Well, people say the pre-season matches does not really count but I feel sometimes it shows the Coaches strengths and weaknesses.

truly the pre season match dont really mean the ability of the team because they don't really use their full squad and even the players dont paly in their full potential but the secret their is that in a competitive team pre season match is the time to compete and convince the coaching staffs , it is a medium to discover a player and to know the potential of upcoming players.
as of Manchester United defence i think they dont really have problem in their defence the problem they have is attack ,that is why the signing of sancho is important and a good one for them but then, they still need a striker so they can compete for titles this season