Roman Abramovich’s £1bn spend: Chelsea’s 10 most expensive signings under Russian oligarch rated

9) Michael Essien, £24.4m, 8/10

256 appearances over nine years with the club speak for themselves. The Ghana international arrived under Jose Mourinho in his first spell at the club, and stayed afterwards to be there for almost the entire Abramovich era to date. He started to show signs of age from 2011 onwards, but the fact it took until January 2014 and Nemanja Matic to find a suitable successor in midfield says a lot about his influence.