Complex sentence: Born in Gernika, Basque Country, Mauri spent 11 seasons in La Liga with Athletic Bilbao, making his debut in the competition on 20 September 1953 in a 2--3 home loss against Real Madrid.
Split into simpler sentences: Born in Gernika, Basque Country, Mauri spent 11 seasons in La Liga with Athletic Bilbao. He made his debut in the competition on 20 September 1953, in a 2--3 home loss against Real Madrid.