John Obi Mikel
It might feel like ex-Chelsea stalwart John Obi Mikel has been around forever, but he was a promising youngster once. The defensive midfielder cost the Blues £16m when he moved from Lyn as a 19-year-old. There was controversy surrounding the move, as it was initially agreed that he’s be joining Manchester United. Chelsea ended up paying the club £12m of the transfer fee as a result.