2. Michael Essien (Chelsea)
Essien became Chelsea’s club-record signing – in an already free-spending era – when he joined them from Lyon in 2005 for £24.4m. But the form that made him one of the world’s finest midfielders in the late 2000s wasn’t displayed during at least his first 12 months at Stamford Bridge.
To accommodate Essien, Mourinho dropped the fluid Eidur Gudjohnsen from a robust team, meaning the quality of Chelsea’s football (if not the results) also suffered when, with Frank Lampard and Claude Makelele still at their peak, there was little need for another box-to-box midfielder. Michael Ballack’s arrival the following summer appeared to put Essien’s place at greater risk, but the Ghanaian responded with consistently exceptional form thereafter and became arguably Chelsea’s most important player until two serious knee injuries forced a premature decline.