“He’s quite unique compared to other sporting directors,” Spanish football expert Guillem Balague told BBC Sport.
“He had no playing career, started in banking, and only got into football later, first at Carpenedolo, an amateur club, then at Parma and Genoa, where he built key connections with Peter Kenyon and Jorge Mendes.
“Under his watch, Atletico won two La Liga titles (2013-14, 2020-21), a Copa del Rey (2013), a Europa League (2017-18), and a Uefa Super Cup (2018).
“He’s seen as the architect of the squad rebuild after the 2014 title-winning team faded.”
Working with manager Diego Simeone, Berta helped Atletico make some astute acquisitions during that rebuild.
France striker Griezmann was signed from Real Sociedad for £24.8m in 2014 and five years later was sold to Barcelona for £103m. Atletico then bought him back in 2021 for just £16.5m.
Spain midfielder Rodri, now a Ballon d’Or winner, was signed for £16.5m in 2018 and sold to Manchester City the following year for £62.5m, while Slovenian goalkeeper Oblak signed from Benfica in 2014 for just £13m. He’s now widely regarded as one of the best goalkeepers in the world.
More recently, forward Julian Alvarez joined from Manchester City last summer for £81.5m and he has scored 23 goals for Atletico this season.
“He brought in key players like Griezmann (twice), Luis Suarez, Kieran Trippier, Llorente, De Paul, and Julian Alvarez,” added Balague.
“But he also had some flops, like Joao Felix, Kalinic, Arias, Torreira, but he always worked within the club’s financial limits.
“In total, he made 52 signings since 2017, spending around 828 million euros (£692m), leaving a big mark on Atletico’s squad. An end of an era for them.”