Reigning US Open champion Coco Gauff will be the top seed at this week’s WTA Toronto event, a hardcourt tuneup for the year’s last Grand Slam showdown, in New York. The second-ranked American is joined by third-ranked Aryna Sabalenka and sixth-ranked defending champion Jessica Pegula in a field where several top players withdrew following the Paris Olympics. Gauff and the other top-eight seeds received a first-round bye, but she will open in the second round against Sofia Kenin or a qualifier. Also in her quarter of the draw are Japan’s Naomi Osaka, a four-time Grand Slam champion, and Tunisia’s Ons Jabeur, who meet in a first-round match. Jabeur withdrew in Washington last week with a right shoulder injury.