Kei Nishikori has been handed a huge boost in his hunt for a third Japan Open title after holder and third-ranked Swiss Stan Wawrinka pulled out with a back problem on Thursday.
World No. 5 Nishikori, who won the singles bronze medal at the Rio Olympics and reached the semifinals at the U.S. Open — where he was beaten by Wawrinka — will now head into the tournament at Ariake Tennis Forest Park, which starts on Monday, as the top seed.
With little downtime in his busy schedule that included leading Japan to a win over Ukraine in the Davis Cup World Group playoff two weeks ago, Nishikori also will avoid playing the in-form 2013 champion and Rio silver medalist Juan Martin del Potro.
The Argentine, who he has never beaten in four attempts, withdrew earlier due to injury concerns.
"I'll look to make my presence felt," Nishikori told a news conference on Thursday. "Mentally, with the rest I had after the summer and the Davis Cup, I've managed to refresh (myself)."
Nishikori will be looking to add to his Japan Open titles from 2012 and 2014 but is not taking anything for granted at the tournament on home soil, despite the notable absentees.
"It's a tough tournament nonetheless," he said. "I'll take each match at a time."