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,[2] going on to finish his first season with 31 games.
Aged only 17, he began playing regularly with the reserves in the Segunda División B. Flaño remained an important fixture with the Navarrese the following campaign.
[4][5] Released in June 2009, he joined CD Numancia on a free transfer for two years, as the Soria side had just been relegated from the top division;[6] he appeared in 40 Segunda División matches in his second season – 39 starts – in a final comfortable midtable position.
[8] On 7 June of the following year, in the last round of the campaign and with the team needing one point to avoid a second consecutive relegation, he scored a last-minute header for a 2–2 draw at CE Sabadell FC.
In the early stages of the following season, both siblings suffered a complete rupture of the anterior cruciate ligament on their left knee, being sidelined for several months.