Sonnen tweets that the McGregor-Mayweather fight is definitely taking place.
Connor vs Floyd is ON!
— Chael Sonnen (@ChaelSonnen) March 17, 2017
He later says he was told the information from a ticketing source:
For some reason, both of these fighters have said they’re fighting, but no reporter has announced it. Now I have information from someone higher than that, which is a guy at a ticketing company where the ‘build’ was sent in…In that industry, [a build] is when you submit to the ticketing company, what you want, what your card is, what your date is — essentially, your schematics, this is what the arena layout is going to look like. That’s called the build, that’s the first step to lining up your tickets. The build was submitted, and I got it right from the ticketing guy. Whether that information is accurate or not, I believe it is. I believe it is enough that I reported it, I tweeted it. I will tell you again, I don’t know how to use any clearer language, Conor and Floyd are going to fight.