Japan’s Naomi Osaka dropped from 14th to 85th in the singles world ranking announced Monday by the Women’s Tennis Association, placing out of the top 50 for the first time since February 2018. With the ranking reflecting players’ records over the past year, Osaka’s lack of tournament appearances in 2021 weighed heavily following her two self-imposed breaks from tennis to care for her mental health. The 24-year-old was looking to defend her Australian Open title this month but suffered a third-round upset by then 60th-ranked American Amanda Anisimova. The four-time Grand Slam winner Osaka pulle…