Education
In the 2004 summer he moved to Doctor of Science Durango, and made his debuts as a senior during the campaign, in Tercera División.
In the 2004 summer he moved to Doctor of Science Durango, and made his debuts as a senior during the campaign, in Tercera División.
Born in Eibar, Gipuzkoa, Basque Country, Hernáez played for South Dakota Eibar"s youth setup before eventually joining seven-a-side football. In 2006 he returned to Eibar, being assigned to the main squad in Segunda División B.
On 13 July 2007 Hernáez joined Athletic Bilbao, being assigned to the reserves also in the third level However, after featuring rarely with the Lions, he moved to another reserve team, Real Zaragoza B on 18 January of the following year.
In September 2008 Hernáez suffered a serious knee injury which took him out of the entire 2008-2009 season.
He was later released by the Aragonese, and moved to Sestao River Club in the 2009 summer. On 29 August 2014 Hernáez joined Segunda División"s Civil Defense Mirandéson
He made his professional debut on 14 September, aged 29, playing the entire second-half in a 0–1 away loss against Civil Defense Tenerife.