5- Carlo Ancelotti
Ancelotti had virtually promised that he was going to part ways with Paris Saint-Germain at the end of last season, and yet it was only Real Madrid who showed real interest in getting him.
The Italian's resume and pedigree at the highest level is almost unmatched, and despite the fact that he has managed at rivals Chelsea, I don't believe his feelings towards the Blues would have caused him to outright reject any advance from Old Trafford.
An old school boss not too dissimilar to Sir Alex in terms of how he interacts with his players, Ancelotti is proven at the highest level and acclimatised to working well under immense pressure.
Due to his time at the likes of AC Milan and PSG he has build up contacts with a number of high profile players that could have come in handy in the transfer window.