Madrid shortly after he did. Brazilian right-back Fabinho, a loanee from Portuguese side Rio Ave, would make only one first-team appearance at the club, but after being reunited with Campos at Monaco a year later, he developed into a €50 million central midfielder.

"He's the kind of player now, when you see him playing at that level [with Liverpool], you realise how good Luis is," Karanka told Bleacher Report.

Campos' colleagues at Madrid were disarmed by his enthusiasm, his diligence and his energy. He used his time at the club to develop a new piece of scouting software, Scouting System Pro, and was never afraid to offer an opinion.

"Luis works in a lot of detail. He's very persistent and always looks for as much information as he can find," recallsJose Morais, who was one of Mourinho's assistants at Madrid. "He's a guy with ideas who's dynamic enough to make things happen. He's a kind of entrepreneur."

Campos, who speaks several languages, was employed to help Madrid identify promising players, and he doubled up as an opposition scout. A central tenet of his approach is his belief that there is no substitute for watching players in the flesh, which means he spends much of his life in taxis, airports and hotels.

"For me, live observation is fundamental," he explained in a 2017 interview with Duncan Castles for Yahoo. "For example, a small detail such as observing how a player warms up before a game or coming on as a substitute reveals much of his character. And character is an essential