Las Vegas, Nevada – Floyd Mayweather Jr., 41-0 with 25 knockouts, will face southpaw Victor Ortiz, 29-2-2 with 22 knockouts, on September 17 at Las Vegas for Ortiz's WBC welterweight crown at the MGM Grand

“I'm aggressive. I'm coming straight ahead,” Mayweather said. “I'm looking for the knockout. He's looking for the knockout. I can guarantee it won't go the distance.”

Ortiz, 10 years younger than Mayweather at age 24, offers Mayweather a southpaw in his prime, what many see as a perfect tuneup fight for Pacquiao but what Mayweather calls a solid test of his conditioning and skills.

“That's why this has been my longest training camp thus far, because we wanted to make sure we're ready for a guy that is 10 years younger,” Mayweather said. “We will be ready.”

Mayweather has not fought since stopping Shane Mosley in May of 2010 and has fought only twice since stopping Britain's Ricky Hatton in December of 2007.

“I haven't showed (ring rust) thus far. I just try to focus on doing my job,” Mayweather said. “I try to be disciplined. I keep myself in shape.”