![Last fight: Floyd Mayweather expects Conor McGregor to fight "extremely dirty" in what will be his last bout in the ring.](http://web.archive.org./web/20170819081743im_/https://www.fairfaxstatic.com.au/content/dam/images/g/x/u/a/h/a/image.related.wideLandscape.460x259.gxzv0p.png/1503112159886.jpg)
Mayweather expects McGregor will fight 'extremely dirty'
​Floyd Mayweather labelled Conor McGregor a "dirty" fighter on Thursday, and admitted he fears the Irish mixed martial arts star will use roughhouse tactics during their boxing match on August 26.