2:46 PM PT -- TMZ Sports spoke with Dana White who says the fight will be a 12 round boxing match. Both guys will use 10 ounce gloves. They will fight at 154 pounds.
The fight will take place at the T-Mobile Arena. Ticket prices have not been set yet.
There WILL be an undercard -- it will be boxing and Mayweather Promotions will handle the matchmaking.
We asked Dana if there was a possibility Roy Jones Jr. will fight Anderson Silva -- he told us, "I highly doubt it.