De la Red collapses

"It appears that he fainted due to the physical effort he was putting in," Real's head of medical services Carlos Diez said.

"He is going to stay in hospital overnight under observation and if there are no complications he will return to Madrid tomorrow. There, we will do more tests to determine the causes.

"All tests at present are normal and he is without any problems."

In the 13th minute of the tie in Irun, De la Red was running back towards the halfway line when, without anyone in close proximity, he suddenly fell face first on to the pitch and lay motionless.

Medical staff were quickly in attendance and the 23-year-old showed signs of movement as he was carried off on stretcher.

He regained consciousness in the dressing room and was taken to a local hospital.

Real Madrid lost the leg 3-2.

The game was only two minutes old when Juan Dominguez burst past Michel Salgado to rock the visitors back with the opener.

Real's Argentine striker Gonzalo Higuain levelled on a counter-attack soon after, but the game had to be halted when De la Red collapsed.

Dominguez was gifted a free header to put the home side back in front after 20 minutes, and Real had to wait until after the re-start before Argentine striker Javier Saviola struck a great equaliser.

Again the modest Basque club hit back when Goikoetxea found space in the area to net the winner in the 63rd, but it will take a massive performance from Real Union at the Bernabeu to put the 17-time Copa winners out of the competition.

Return matches are scheduled for November 12.