Athletic Club's most expensive departures

In a world football clubs spend lavishly on exports from across the world, Athletic Club have taken pride in retaining their Basque-only policy which champions players from the local area.

Every single one of Athletic Club's players was either born in the Basque Country or brought up in the region, which consists of the following territories: Biscay, Gipuzkoa, Alava, Navarre, Labourd, Soule and Lower Navarre.

Despite the notable limitations of the policy, Athletic Club have still managed to enjoy great success and Bilbao's Cantera has been a consistent production line that's churned out several gems through the years.

While Athletic Club have been reliant on their academy, they've not sold many players for extortionate sums - only five players in their history have departed for more than €10m.

Kepa Arrizabalaga is Athletic Club's most expensive departure after the goalkeeper joined Chelsea in 2018 for €80m (£71.6m).

The Spaniard remains the most expensive goalkeeper in football history with his transfer fee surpassing the previous record set by Alisson's move from Roma to Liverpool a month earlier.

Ranking second is Aymeric Laporte, who at the time was Manchester City's record signing when he traded the Estadio San Mames for Pep Guardiola's charges at the Etihad Stadium in January 2018.

Laporte's transfer fee exceeded Athletic Club's previous record sale of €40m for Javi Martinez, who joined Bayern Munich in August 20212 in what was then the most expensive transfer in Bundesliga history.

Interestingly, all three of the aforementioned players were 23 years old at the time of their transfer.

Ander Herrera went close to emulating Martinez's transfer fee when he joined Manchester United in 2014, while left-back Asier del Horno completes the top five following his €12m switch to Chelsea in 2005.

Of those ranked sixth to tenth, legendary striker Aritz Aduriz is arguably the most notable, having completed a €6m move to Real Mallorca in 2008 before retuning to Athletic Club in 2012, where he scored 149 goals in 313 appearances.

Middlesbrough, Nottingham Forest and Birmingham City will all be aware of Aitor Karanka following his managerial spells with the club, but the former centre-back is also Athletic Club's seventh-most expensive player sale.

Athletic Club's top departures

1. Kepa Arrizabalaga - Chelsea (€80m)

2. Aymeric Laporte - Manchester City (€50m)

3. Javi Martinez - Bayern Munich (€40m)

4. Ander Herrera - Manchester United (€36m)

5. Asier del Horno - Chelsea (€12m)

6. Unai Nunez - Celta Vigo (€7m)

7. Aitor Karanka - Real Madrid (€6m)

8. Aritz Aduriz - Real Mallorca (€6m)

9. Bixente Lizarazu - Bayern Munich (€4.5m)

10. Xabier Eskurza - Barcelona (€4m)