Rafael Nadal will make his return from injury in Spain's Davis Cup quarter-final against Germany in Valencia on Friday.

The 16-time grand slam champion, who this week moved back to the top of the rankings, has not played since retiring from his Australian Open last-eight encounter with Marin Cilic due to a hip injury.

Nadal will be back in action on clay in his homeland for the second rubber against Germany's number two Philipp Kohlschreiber.

Asked how close to being 100 per cent fit he is, the 31-year-old said: "I was not very good in mathematics at school. So I don't know about percentages, but I am here to play, and to play as well as possible.

"From the beginning, my idea was to be here, but we have to be respectful with the injury. He [Spanish captain Sergi Bruguera] believes I am ready, and I believe too."

Nadal has not lost a set in five clay-court contests with Kohlschreiber and has a 100 per cent record in his 17 clay-court matches in the Davis Cup.

David Ferrer will face world number four Alexander Zverev in the opening rubber.