A product of hometown CA Osasuna's youth system, Flaño was born in Pamplona, and he made his debut with the first team in a La Liga 2–1 home win against Villarreal CF on 28 August 2005, going on to finish his first season with 31 games.
Flaño, a product of Osasuna's youth academy, was born in Pamplona and made his professional debut for the club in a La Liga match against Villarreal CF on August 28, 2005. He played 31 games during his first season.