After being omitted from Luis Enrique's first selection since taking charge after the disappointing World Cup campaign in Russia, midfielder Koke is in line to feature in next Thursday's friendly against Wales and the Nations League meeting with England on October 15.
However, there is no place for striker Costa, who assisted Antoine Griezmann's second goal in a 3-1 win against Club Brugge on Wednesday before being replaced due to a thigh problem.
Jordi Alba continues to be overlooked by the former Barcelona coach, with Marcos Alonso and Jose Gaya picked as the left-back options instead.
Wolves defender Jonny Castro Otto received his first call-up, while Marc Bartra and Paco Alcacer are welcomed back into the fold.
Real Madrid pair Dani Carvajal and Isco are both sidelined, ruling them out of contention.
Spain travel to Cardiff to take on Wales, whose squad includes Gareth Bale despite him missing Real Madrid's shock Champions League defeat to CSKA Moscow through injury, before hosting England in Seville.
Spain squad in full:
Defenders: Cesar Azpilicueta (Chelsea), Jonny Castro Otto (Wolves), Jose Gaya (Valencia), Marcos Alonso (Chelsea), Sergio Ramos (Real Madrid), Marc Bartra (Real Betis), Raul Albiol (Napoli), Nacho Fernandez (Real Madrid)