Mayweather vows to floor McGregor

[caption id="attachment_215429" align="aligncenter" width="591"] Boxer Floyd Mayweather prepares for a workout this week ahead of his match against Connor McGregor, which could be one of the richest fights in history
Picture: Reuters[/caption]

Floyd Mayweather has said he has done his homework on mixed martial artist Conor McGregor and promised their multimillion dollar fight in Las Vegas on August 26 will not go the distance.