Japan's Kei Nishikori became the latest withdrawal from the ATP Masters 1000 tournament in Toronto on Wednesday with a shoulder injury.
Nishikori, a finalist at the Canadian hard court stop in 2016, had been set to face seventh seed Hubert Hurkacz of Poland in a second-round clash on Wednesday but dropped out complaining of right shoulder pain.
"I am disappointed to announce that I have decided to withdraw from my match today,” Nishikori said in a statement. "The right shoulder is very sore after a long stretch of tennis and I do not want to risk further injury.
"I will now spend my focus on getting healthy and back on court again.”
Hurkacz will receive a walkover into the third round, where he will face Georgian Nikoloz Basilashvili.
Nishikori's sudden withdrawal follows world number four Rafa Nadal's exit on Tuesday due to persistent pain in his injured left foot.
The injury kept the 20-time Grand Slam champion out of Wimbledon and the Tokyo Olympics this year and played a role in his shock third-round exit at the Washington Open last week.
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