Novak Djokovic is two steps away from successfully defending his Madrid Open title after being handed a walkover win in his quarter-final with Kei Nishikori.

The world number two was due to face Nishikori on Friday morning in the Spanish capital, but a recurrence of a wrist injury forced his opponent to withdraw.

Djokovic, who required three sets to overcome Nicolas Almagro in the last round, will take on either David Goffin or Rafael Nadal in Saturday's semi-final.

It is a disappointing end to the tournament for Nishikori, meanwhile, having also been forced to pull out of the Barcelona Open recently.

"If you push too much you have more chances to get injured and it can be a big problem," he said. "That's why I chose not to play today."

Goffin and Nadal are scheduled to face off on Friday afternoon.