#9 Paulo Ferreira (£1.8m from Vitoria Setubal/£18m from Porto)
Paulo Ferreira is probably one of the most underrated full-backs of all time. However, as long as one of his greatest fans was his manager, he surely did not mind. The Portuguese is one of several players on this list that played under Mourinho at multiple clubs.
Ferreira was brought in as one of Mourinho's first transfers as the manager of FC Porto in July 2002 and then immediately followed him to Chelsea in 2004 after winning the Champions League.
Ferreira won 10 major trophies under Mourinho's stewardship and was one of his most trusted defenders. After the Special One's departure, Ferreira added another five titles to his name, although his playing time slowly diminished.
The Portuguese right-back was one of the hard workers that are at the core of Mourinho's teams and he never really got the credit he deserved until he retired in 2013.