Mikel Arteta never made it at Barcelona but he knows from first-hand experience how a functioning youth system can transform a club.
The Arsenal manager left his home in San Sebastian at the age of 15 to join Barca's famous academy boarding school, giving him an insight into an unlikely group of teenagers would revolutionise a club and turn it into the greatest in the world football.
The great Barca team that dominated Europe from 2008 to 2015 was formed largely of youth team players, many of them who had come to Barcelona to live in the reconverted 18th century farmhouse known as La Masia, where the club housed out-of-town teenage prodigies.