There is not a single mention of Guy Hillion on the official Chelsea website. He's unlikely to show up in any official publication. Yet he's a familiar name if you've ever played as Chelsea in Football Manager or if you followed the Eden Hazard and Gael Kakuta transfer sagas.
By all accounts, 65-year-old Hillion is a respected scout who signed with Chelsea in 2006 to work with Frank Arnesen after stints at FC Nantes, Bordeaux, and Rennes. He did leave for a few months in 2011 to work in Nantes' front office, but he returned shortly thereafter and was instrumental in Chelsea's pursuit of Eden Hazard. While I'm sure it wasn't all that hard to look at Hazard at Lille and proclaim him a future star, Hillion's consistent positive reports helped convince the club to shell out the outrageous sum of money required to secure the Belgian's services.
So when a man like Hillion talks about a prospect, you listen. Like any other advisor, that doesn't mean you'll follow everything he's recommending, but you'll listen.
"I have seen [Giannelli Imbula] often. As soon as he gets the ball he is able to accelerate and break through the lines. He covers well, has good technique, great vision of the game, with a very good quality pass and a great left foot. He doesn't have bad qualities for a midfielder."
-Guy Hillion; source: Le 10 Sport via Inside Futbol
It's probably safe to assume that Chelsea are indeed listening. Whether that listening will turn into purse-string-loosening or Arsenal-bid-hijacking for the 21-year-old remains to be seen obviously.
Imbula has been linked with Chelsea (and Arsenal) in the past, although he chose to stay in France and join Marseille instead from freshly promoted Guingamp just a few months ago for less than €8m. His performances in OM's double pivot have been eye-catching enough however to have already reignited the transfer rumor mill.
At this point you may start wondering about or looking for a scouting report, but let me save you the trouble. While Imbula has represented France at U21 level, he was in fact born in Belgium. BELGIUM. Sign him up!