|Full name||Iago Herrerín Buisán|
|Date of birth||25 January 1988|
|Place of birth||Bilbao, Spain|
|Height||1.87 m (6 ft 2 in)|
|2007||→ Barakaldo (loan)||18||(0)|
|2010–2012||Atlético Madrid B||75||(1)|
|2012–2013||→ Numancia (loan)||34||(0)|
|* Senior club appearances and goals counted for the domestic league only and correct as of 15 September 2014.
† Appearances (Goals).
Born in Bilbao, Biscay, Herrerín was a product of Athletic Bilbao's youth ranks. He played a couple of months with the farm team CD Baskonia, being loaned to Barakaldo CF in January 2007. After returning in the summer he was assigned to the B-team, also in Segunda División B.
In July 2010 Herrerín decided to leave Athletic in search for "a new life in football", signing a contract with Atlético Madrid and playing two full seasons with the reserves, also in the third level. On 8 January 2011, in a match against neighbouring Getafe CF B, he scored the 3–2 winning goal for the hosts in the 72nd minute.
Herrerín returned to Athletic Bilbao in the 2012 summer, signing a two-year deal and immediately being loaned to CD Numancia in a season-long move. On 18 August he made his Segunda División debut, in a 2–0 home win against Sporting de Gijón.
In July 2013 Herrerín signed a new contract extension with the Lions, and was definitively promoted to the main squad. On 23 August he played his first match in La Liga, keeping a clean sheet in a 2–0 win over CA Osasuna at the Anoeta Stadium; he spent his first year, however, as backup to longtime incumbent Gorka Iraizoz.
- Iago Herrerín, cedido al Barakaldo (Iago Herrerín, loaned to Barakaldo); Athletic's official website, 7 January 2007 (Spanish)
- Iago Herrerín y Andrés Muñoz echan el cierre a la portería del Atlético B (Iago Herrerín and Andrés Muñoz close Atlético B's goal); Atlético's official website, 30 July 2010 (Spanish)
- Iago revivirá su mejor día (Iago will look back on his best day); Diario AS, 13 November 2011 (Spanish)
- El Athletic ficha al portero Iago Herrerín y lo cede al Numancia (Athletic signs goalkeeper Iago Herrerín and loans him to Numancia); Marca, 1 July 2012 (Spanish)
- El Sporting se estrella en su debut en Soria (Sporting crashes in debut in Soria); Marca, 18 August 2012 (Spanish)
- Iago Herrerín renueva con el Athletic hasta 2016 (Iago Herrerín renews with Athletic until 2016); Diario AS, 15 July 2013 (Spanish)
- Athletic Bilbao 2–0 Osasuna: Los Leones see off Basque rivals at the Anoeta; Inside Spanish Football, 23 August 2013