Luis Enrique said Spain lacked "finesse" during their "uninspiring" 1-1 draw with Greece, while admitting "it is a result I did not expect".
Spain were held at home in their opening 2022 World Cup qualifier on Thursday night, with an Anastasios Bakasetas penalty cancelling out Alvaro Morata's stunning opener.
Enrique was left frustrated by his team's failure to carve out clear-cut openings after heading into the game confident of victory.