The world and European champions went 2-1 down in Bari, with Alberto Aquilani scoring the winner with six minutes remaining, after Xavi Alonso had cancelled out Riccardo Montolivo's opener from the spot.

"We started out really shyly," Del Bosque said afterwards.

"I am really happy with the second half, though. Generally speaking, this was a good match.

"But in the second half, when we had improved, the defeat happened."

Chelsea striker Fernando Torres gave his club a scare when he went off with concussion, which was not thought to be serious, while Gerard Pique and Andoni Iraola also limped off.

After the game, captain Iker Casillas, the Real Madrid goalkeeper, expressed his thoughts about the potential of a strike at the start of the Primera Liga season.

A dispute has been ongoing about what would happen to players' wages in the event of their clubs being declared insolvent.

"To my knowledge, the start of the league is compromised," he was quotes as saying in Marca.