Floyd Mayweather Jnr says his many legal headaches, including a defamation lawsuit filed by Filipino star Manny Pacquiao, will not distract him from next week's title fight with Victor Ortiz. Unbeaten Mayweather, 41-0 with 25 knockouts, will face American southpaw Ortiz, 29-2-2 with 22 knockouts, on September 17 at Las Vegas for Ortiz's World Boxing Council welterweight crown. "I'm aggressive. I'm coming straight ahead," Mayweather said Wednesday. "I'm looking for the knockout. He's looking for the knockout. I can guarantee it won't go the distance." What has gone the distance are the court cases involving Mayweather, who faces up to 34 years in prison if convicted on all charges in a domestic violence dispute from last September involving former girlfriend Josie Harris. Pacquiao, 32, is suing Mayweather for defamation, saying the American dubbed him a dope cheat when pushing for extra blood tests for a much-awaited showdown that fell through when contract talks broke down in 2008. "I never accused nobody of doing anything," Mayweather said, although he later cited Pacquiao's reluctance to take the test and rise to power by saying, "it's obvious you must be hiding something. "If a fighter beats me, I want him to do it the fair and honest way. "If you're the best, take the test." A fight fan and a housing community security guard also have suits against Mayweather, who shrugged off the distractions. "I keep a clear head. I don't focus on nothing," Mayweather said. "Things happen in life. It's a roller coaster ride. Everything happens for a reason. Certain obstacles are put in front of me. I just feel no one can stop me." What could stop him are felony counts of grand larceny, coercion and robbery from an altercation with his former girlfriend. Mayweather said Harris claimed she was punched, stomped and beaten by him but added, "We're yet to see photos", and indicated drugs and alcohol could have been involved in perceptions of the incident. "There's a difference between holding somebody's hand and restraining someone," Mayweather said. Mayweather said he had "spoken enough" about whether or not he still wanted to fight Pacquiao, even as critics have charged he used the blood tests as a way to avoid a fighter who might beat him. Mayweather talked about how boxing was tainted by doping then how Pacquiao started rising among the ranks of top fighters later than some other fighters. "Let's make this make sense," Mayweather said. "I was born at night but not last night. I was born in the day but not yesterday. My health is more important than money." Mayweather said Pacquiao keeps talking about Mayweather and fighting foes whom Mayweather has already beaten because it makes the Asian star more money. "As long as he's attached to Floyd Mayweather, he's going to make great paydays," Mayweather said. "As long as he's fighting Floyd Mayweather's leftovers he's going to look great. Fighters are never the same once they face me." Mayweather said he would fight England's Amir Khan, provided Khan first beat undefeated American Jesse Vargas, who fights on the Mayweather-Ortiz undercard. "He's got to earn it," Mayweather said. "If Amir Khan gets past Jesse Vargas, Amir Khan has a fight with Floyd Mayweather." 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." Mayweather is engaged to model Shantel Jackson, saying her strength has helped him through the tough times. "Going through everything, it's nice to have a strong lady behind you," said Mayweather. "She has never judged me. She says we live and learn. She doesn't judge me. She is very important in my life."