It was reported not too long ago that Floyd Mayweather
would be in fact fighting Andre Berto for his 49th and final fight of his boxing career. The date would be on September 12th. However, nothing is fully confirmed yet, and Mayweather could face a different opponent on a different date.
According to one source, Money Mayweather is choosing between Amir "King" Khan and Berto, with the dates being on September 19 and September 12, respectively.
https://twitter.com/latimespugmire/status/615646076100415489
We'll see what happens as time progresses.