Atlanta United star Josef Martinez underwent surgery on his right knee Wednesday, more than two weeks after he tore the ACL during the league-opening match at Nashville. Martinez posted an update on his Instagram page after the operation at University of Pittsburgh Medical Center. Also performing the surgery was Dr. Freddie Fu, the Pittsburgh-based orthopedic specialist who was hailed for saving Zlatan Ibrahimovic’s career after the star striker ruptured knee ligaments in 2017.