It will be very tight - though oddly enough I have seen more weaknesses in the Spanish side.
When they get rattled they look vulnerable and Korea will rattle them, make no doubt about that.
The heat may well be a factor too as Spain are used to playing in the evenings, but they have had a couple of extra days to recover.
But Korea are probably the fittest side at this tournament.
That probably counts for a lot, as their players are playing in a less competitive league and come into this tournament fresh.
Going forward they are always a threat and they just keep coming at you the whole time.
And when they have to defend the work they get through is astonishing.
The support in all the Korean matches has gone beyond the hysteria level, but now it is reaching insane levels.
We were sitting in the ground some time after the game and there was still noise around the place.