Canelo Alvarez wants to open a can of whoop-ass on Lionel Messi -- the boxing superstar blasted the Argentinian striker for seemingly disrespecting his home country after defeating Mexico in the World Cup.
Canelo's rage stems from a viral video of Messi celebrating with his teammates after Saturday's 2-0 win ... which shows a Mexico jersey lying on the ground near his feet.
Some -- including Alvarez -- believed Messi was intentionally displaying his contempt for El Tri ... as he appears to kick the jersey in the video.