Alvaro Morata’s 33rd-minute opener wasn’t enough to secure Spain a victory on their World Cup qualifiers as their manager was left frustrated by his team's failure.
"Against a retreating rival like Greece that has a strong physical level and that defensive precision we have lacked finesse," the La Roja boss told reporters.
"With so little space [against that defence] we have been uninspiring. Obviously it is a result that I did not expect.
"We have not generated the flow of chances to be able to score more goals. My job is to try to help the players.
"You have to try to solve the games against all the rivals. Greece has come to play their game.
"Every game has its complications and today Greece defended very well."
On Sergio Ramos’ substitution at the halftime, Enrique said: "He was perfectly fit to play," he said. "But we had already talked and we decided that he would only play the first part [of the match]."
Spain will face Georgia on Sunday, three days before they are due to play Kosovo.