The source cites the fact that Ryan has contracted his cartoonishly large stomach and filled his lungs with enough breath to conceivably pass through his vocal chords, an evolutionary process generally befitting a human being who is about to form sounds, as evidence that Rex Ryan is about to say something. As to why it's assumed the content of his speech will be asinine in nature, the source referenced the fact Rex Ryan is a fking idiot who says stupid things literally all the time.
Speculation has already begun over what exactly Ryan is going to say. According to an ESPN.com InstaPoll, 20-percent of those questioned feel he'll make a baseless prediction regarding the Jets' success in the upcoming season, with 35-percent predicting he'll continue his long-standing tradition of launching into an expletive-laden tirade about something no one even asked him about. The remaining 45-percent assume he'll insult an opponent who has enjoyed infinitely more success than Ryan has up to this point in their respective NFL career.
UPDATE: The Associated Press has confirmed the thing that Rex Ryan said was some confusing football-military combat analogy that no one really understands but is pretty sure is insulting to every member of the U.S military and their loved ones. A follow-up question was not asked because, really, what's the point?
In other NFL news, several news outlets have reported that New England Patriots quarterback Tom Brady is about to get dressed and will almost definitely put on some article clothing that looks completely retarded.