Per ESPN Deportes' A Los Golpes (h/t ESPN News Services), Alvarez called Kovalev a "bad boxer" and "bad loser" in response to Kovalev's concerns regarding his quick training turnaround after his Aug. 24 victory over Anthony Yarde.
"Weight is not an excuse," Alvarez said regarding Kovalev's fight to make weight.
Alvarez also owns light middleweight, middleweight and super middleweight titles.
Mayweather beat Alvarez by majority decision in 2013: 116–112, 117-111, 114-114.
Alvarez also had words for Gennady Golovkin, whom he beat via majority decision in September 2018 in a rematch of their draw one year earlier.