it will indeed be a tough task for Manchester United. but if MU can be consistent with his ability then it can be done. But now Manchester United really have to focus on preparing to face Chelsea on Matchday 13. Because now Chelsea have really found their game back to being consistent thanks to their new coach, Potter. even a big club like Milan had to lose 3-0 to Chelsea. so it's clear how strong chelsea is now. But actually MU from every match we can see an increase in performance even if little by little.
I don't just see Chelsea as a tough opponent for Manchester United, because there are some really strong teams in the Premier League this season and they are all above Manchester United. It is true that Chelsea are currently starting to show very good performances under Potter, but the good results obtained by Chelsea have only been a few times in the last few matches so far, so it is still too early to judge that now because Potter himself has not yet long time coaching Chelsea, although the results are very visible now.