The path to this showdown has been convoluted and controversial. The two first fought in 2017, when Canelo held Golovkin to a highly debatable draw. They were due to rematch in May, only for Alvarez to fail two drug tests for traces of clenbuterol. Canelo claimed he had inadvertently eaten contaminated meat but eventually pulled out of the fight. He was ultimately handed a six month ban, backdated to his first failed test in February. He is therefore able to box in September and has announced that he will enter year round drug testing.
Golovkin was the holder of three of the major world titles but has been stripped of the IBF version after declining to agree to box his mandatory challenger for that belt, Sergey Derevyanchenko. The Kazakh remains the unified WBC and WBA middleweight titlist.