3. Mikel San Jose
Mikel San Jose began has career at Liverpool in 2007 but failed to break into the first-team.
Due to this, in 2009, he was sent on loan to Athletic Bilbao before signing permanently in 2010.
The defensive midfielder has gone onto make 147 appearances for the La Liga club, scoring 19 goals and impressing in the middle of the park.
As well as the holding role, the 26-year-old can also play at centre-back and so his versatility is a very useful asset to the national team squad.
He won the 2007 U-19 European Championship with his country and made his senior debut in August 2014.
Del Bosque may well look to San Jose at the Euros to provide cover for first choice defensive midfielder Sergio Busquets, should the Barcelona star pick up an injury.