Inter Milan boss Jose Mourinho is returning to the Premiership for the first time since his departure from Chelsea in 2007.
Mourinho will watch Chelsea's title crunch match at Manchester United on Sunday, says The Sun.
The Inter Milan boss is spying on United ahead of the two sides' Champions League last-16 clash.
He is due to sit in the Old Trafford directors' box along with Chelsea owner Roman Abramovich.