If Sanchez were to join us, I really don't see him playing as a winger; we already have players blessed with greater pace who can stay out wide and damage teams. Instead, I see him playing more inside and interchanging with Silva and de Bruyne, either of whose absence in recent seasons has been keenly felt. It was notable that MOTD highlighted how many times he completely opened up United with his passing yesterday, and all those moments came when he was playing inside and not in a kid's pocket.
For what it's worth, he did an interview with Arsenal television last week in which he stated his disappointment with the season and his burning desire to win leagues regularly and especially the Champions League. I'd like to see him join us, but I suspect he may be heading to Bayern Munich.