While we could not hear what Reaves was saying in this clip, its probably a good thing as we could tell what he was saying. Thanks to the extreme close-up view of Reaves's face, it was pretty obvious what he was saying to anyone who can read lips even a little bit.
Seems like Reaves was calling Perry out for being a fake tough guy. While the former has earned a reputation as one of the league's best fighters, Perry has had a reputation throughout his career as someone who will get in your face, maybe take a bad slash or a gloved punch here and there, but would rarely actually drop the gloves. Needless to say, these two players do not appear to get along very well.
