MADRID (AP) -- Defending champion Novak Djokovic moved into the Madrid Open semifinals when Kei Nishikori withdrew before Friday's match because of a wrist injury.
The sixth-seeded Nishikori said his wrist was "not 100 percent" and he didn't "want to risk" a more serious injury.
"I don't want to go too hard on my wrist," the Japanese player said. "I want to get back to 100 percent. I want to fight again in every match."
Nishikori, who beat Djokovic in the 2014 U.S. Open semifinals, was playing in his first tournament since March. He withdrew from the Barcelona Open last month because of the lingering wrist inflammation.
A finalist in Madrid in 2014, Nishikori had lost the last 10 matches against Djokovic, including in the semifinals in Madrid last year.
Nishikori said he will "take a couple of days off" and try to recover in time to play in Rome next week and then in the French Open at the end of the month.
"I will plan to play Rome, but we'll see," he said. "I cannot promise to play or pull out right now. But the French is more important. We'll see in the next couple of days."
The second-ranked Djokovic will play either Rafael Nadal or ninth-seeded David Goffin in the semifinals.
Djokovic hasn't played in the semifinals of any event since winning the title in Doha at the beginning of the year. He lost to Goffin in the quarterfinals in Monte Carlo, his first clay tournament of the season.
Djokovic had to withdraw from the Miami Open because of an elbow injury.