MONTREAL — Naomi Osaka pulled out of the National Bank Open hard-court tuneup to be played in Montreal this month ahead of the US Open. The tournament announced the withdrawals of Osaka and two other top-10 players who have won Grand Slam titles, Sofia Kenin and Iga Swiatek, on Tuesday. Osaka is coming off a third-round loss at the Tokyo Olympics, where she had the honor of lighting the cauldron during the opening ceremony. Before that, the 23-year-old Osaka had not competed anywhere since withdrawing before her second-round match at the French Open, citing the need for a mental health break. She also sat out Wimbledon entirely. She is ranked No. 2 and is the owner of four major championships, all on hard courts, including this year’s Australian Open. The fourth-ranked Kenin, who won the 2020 Australian Open, has been sidelined by a foot injury since Wimbledon. No. 8 Swiatek, last year’s French Open champion, lost in the second round of the Olympics. The tournament begins Aug. 9.