Naomi Osaka withdraws from National Bank Open in Montreal

World No. 2 Naomi Osaka has withdrawn from this month's National Bank Open in Montreal, Tennis Canada announced on Tuesday.

No. 4 Sofia Kenin of the United States and No. 8 Iga Swiatek of Poland have also opted out of the tournament. No. 3 Aryna Sabalenka of Belarus became the first seed.

Previously known as the Rogers Cup, the National Bank Open serves as a tune-up event for the U.S. Open. The women's tournament will take place in Montreal from Aug. 7 to Aug. 15, while the men's matches will happen in Toronto on the same dates.

"I am sorry to be missing out on Montreal this year," said Osaka in a statement. "Sending my best to all the fans there, the tournament and the staff. I hope to see you all in Canada next year."

Osaka recently represented Japan at the Olympic Games in Tokyo, losing in the third round to Marketa Vondrousova of the Czech Republic, who went on to win the silver medal.

"I am very sorry but this year I will not be able to play in Montreal," said Swiatek. "The first part of the season was so intense that I need a couple of days off to rest and prepare for the next few months. I'm looking forward to playing in Canada in 2022."

Swiatek also competed in Tokyo, losing in the second round to Spain's Paula Badosa.

Kenin is still dealing with a foot injury that has her sidelined since Wimbledon.

"I'm really disappointed to withdraw from the event in Montréal next week," said Kenin. "While I'm making progress, my foot injury is not where I need it to be to play at the highest level. I feel another week of recovery and rehab is necessary."

On the men's side, World number one Novak Djokovic, a four-time champion in Canada, has also withdrawn from the National Bank Open.