McGregor pokes fun at Mayweather for insisting he's retired

Floyd Mayweather tweeted Tuesday he's "happily retired" and that an agreement to fight Conor McGrgeor isn't a done deal, contrary to recent reports.

McGregor responded later that same day, and in signature fashion, the Irishman's shot at the former boxer wasn't subtle:

Mayweather retired in September 2015 after extending his unbeaten record to 49-0 against Andre Berto, but the prospect of a superfight with McGregor has brought the star boxer to the brink of a return.

McGregor is reportedly in Sin City to discuss his request for a rehearing of his disciplinary case with the Nevada State Athletic Commission.

Mayweather lives and trains in Vegas.