Sylvester Stallone is speaking on Carl Weathers' sudden death -- and it couldn't be more emotional and heartfelt .... yeah, this one's a tear-jerker.
The actor posted a video Friday just hours after news broke that his 'Rocky' costar had passed away the day prior -- and you can tell Sly is absolutely torn up about it ... fighting back tears as he honors his longtime friend and companion in the ring.
Sly says he owes so much of his career and success to Carl .