Wikipedia - Jason Kubler
Jason Murray Kubler ( KOOB-lər; born 19 May 1993) is an Australian professional tennis player. He has a career-high ATP singles ranking of No. 63 achieved on 24 April 2023 and a doubles ranking of No. 27 achieved on 22 May 2023. Kubler's career highlight came at the 2023 Australian Open, where he won his first Grand Slam doubles title as a wildcard alongside compatriot Rinky Hijikata.
Despite a promising junior career, which included the junior world No. 1 ranking and comparisons to Rafael Nadal, Kubler has spent the majority of his professional career on the lower circuits due to a hereditary knee condition that results in weakened meniscus around the joints. The condition has plagued Kubler throughout his career, resulting in six knee surgeries. Kubler also spent four years of his professional career playing exclusively on clay courts to avoid further structural damage to his knees.