Juan Cuadrado (£27m Plus Mo Salah on loan)
In hindsight, this probably looks like the worst deal during Mourinho’s time in charge. However, not many thought Salah was good enough when he arrived at Stamford Bridge so his temporary move to Italy wasn’t a surprise.
However, Cuadrado was a major disappointment. The Colombian made only 15 appearances after joining in February 2015 before being shipped out on loan himself to Juventus just six months later.