The Atletico Madrid midfielder has developed into one of the best playmakers in European football over the last couple of seasons, having helped his side to the La Liga title and the Champions League final.
His presence in the Spain XI has thus far been limited due to Del Bosque favouring experience, but the likes of Xavi and Xabi Alonso have recently retired from the national team and Koke is seen as their successor in the middle of the park by Del Bosque.
"Xavi Hernandez and Xabi Alonso are part of history. The new, as in the case of Koke, will sustain our midfield," Del Bosque has been quoted as saying by AS.
Spain face Macedonia in their opening Euro 2016 qualifier on Monday.