The Red Devils came from behind to defeat the Royals 4-3, and with Manchester City and Chelsea both dropping points over the weekend, the three points gained now see Sir Alex Ferguson's men skip a full win ahead on top of the table.
But make no mistake, the result was not one that Manchester United fans or management will be pleased with, and several big questions still hang over the club heading into Christmas and the subsequent winter transfer window.
Let's take a look at some of those big questions now.
What's the deal with the defense?
It seems like the same comments are being made every week about Manchester United's defense. When the same problems present themselves week in and week out, it's only natural that the same concerns are being raised.
The Red Devils conceded first again on the weekend and let in three goals to lowly Reading—a sign that will not give Sir Alex Ferguson a great deal of confidence heading into their all-important Manchester derby in a couple of weeks, which we'll get to in a minute.
The veteran manager spoke out about his side's defensive lapses following the bizarre victory, stating via BBC Sport (h/t Goal):
It was agony, the worst defending this season, without a doubt. To lose three goals in that manner—we've got to do something about that.
We need to sort that out, or we'll get battered. We deserved to be battered today. If you make mistakes like that defending you’re going to have to do rescue jobs every week. Today again was a rescue job.
Perhaps the biggest concern for United will be how soft the goals were that were scored against them—as they have been all season from their opponents.
United have posted just two clean sheets at home this year and one away from Old Trafford, something that simply must change soon if they are to continue their reign on top of the Premier League ladder.
How should United approach the Manchester derby?
Easily United's biggest match of the year is coming up next weekend in the Premier League, with the Red Devils taking on cross-town rivals Manchester City at the Etihad Stadium.
The match will obviously have the derby aspect to it, but plenty more will seemingly be at stake in this one. After all, Ferguson will no doubt want revenge on Mancini for the two defeats and title loss that he suffered last season to the Citizens, but even for this year, the title race could be largely influenced by the outcome of this very fixture.
Thus, it seems obvious that United will approach the Manchester derby with the utmost importance and are likely to rest plenty of their key players from their Champions League team that will battle CRF Cluj during the week.
United have sewn up Champions League qualification and have nothing to play for, meaning that they will rest any player likely to have an impact on Sunday.
The next thing to consider is how they will approach the match in terms of starting formation and tactics—the least of which is how do they contain the many attacking assets that City have in their starting side.
You'd have to think that David De Gea would start in goals ahead of Anders Lindegaard—especially given his recent performance—and that the usual backline of Patrice Evra, Jonny Evans, Rio Ferdinand and Rafael Da Silva will line up ahead of him, though there is speculation that captain Nemanja Vidic could make a shocking return for the match (per The Daily Mail).
Midfield wise, Tom Cleverley will likely play in the holding midfielder role with most probably Michael Carrick alongside him—a combination that is starting to bear some fruit for the Manchester club this year.
Wayne Rooney, Robin van Persie and Antonio Valencia will all also start for United, meaning that the likes of Anderson, Danny Welbeck and Javier Hernandez will be in great competition with each other for the final starting position in the side.
Plenty of options for Ferguson to consider there.
What role will Shinji Kagawa play when healthy?
There is one final question to consider here for United, and it's probably not quite given the attention that it deserves given the Red Devils rich run of form.
With Wayne Rooney playing so well in a sort of No. 9 or No. 10 role for United, what role will Shinji Kagawa play for the Red Devils when he returns from injury?
The Japanese international was being utilized behind Rooney and/or Van Persie in the middle of the field and also spent some time out on the left wing in the midfield diamond formation, but will he assume that role again when he returns?
Will Ferguson opt to keep the England international Rooney in behind RVP given his strong performances of late, thus shifting Kagawa out to the left or right? And if that happens, what will that mean for the likes of Nani, Ashley Young and Antonio Valencia as United's wingers?
Granted, there are plenty of competitions and matches to be played throughout the remainder of the year, and many formations and combinations will be used—meaning that the question doesn't have to be completely answered by the time Kagawa returns.
But in the New Year, United play some very important matches in quick succession and will want their best team available for those fixtures.
What that best team is, and how it includes Kagawa, is still up in the air.
What are the biggest questions facing Manchester United at the moment?
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