7. Andriy Shevchenko | Retired
Highest market value: £57m (d.o.v - June 1 2006)
Current market value: N/A
Shevchenko's value peaked at just the wrong time for Chelsea. It would never again hit the heights of his AC Milan days, and Roman Abramovich bought the Ukrainian at the very worst possible time - at his most expensive.
From then on, the ageing forward would only depreciate. He eventually left for Milan on loan two years later, and then for Dynamo Kiev permanently.