Arsenal rejected the chance to sign Real Madrid midfielder Fede Valverde as a teen.
The Uruguay international trialled in London as he prepared to leave Penarol.
However, then manager Arsene Wenger was not impressed and snubbed the chance to sign him. Mundo Deportivo says Arsenal were offered Valverde at the time for 4m.
But the Gunners chose to pass on the youngster, who would eventually sign for Real Madrid.
Valverde eventually signed for Real in 2016 for the same fee and is now rated at 100m.