UFC Light Heavyweight Stephan Bonnar, whose 2005 fight against Forrest Griffin on Spike TV's first ever Ultimate Fighter Finale helped break the sport into the American mainstream, is facing Middleweight champ Anderson Silva at UFC 153 in Rio de Janeiro, Brazil this Saturday.

Bonnar spoke to Thomas Myers of MMA Mania in an exclusive interviewand was totally open about his apprehension at facing the best MMA fighter of all time.

Thomas Myers (MMAmania.com): Are you scared, nervous, excited ... all of the above?

Stephan Bonnar: I'm shitting in my pants. But, I'll tell you what, fear is the best motivator.

Thomas Myers (MMAmania.com): Is this a new feeling?

Stephan Bonnar: It's different, for sure. But, I'm actually more nervous for other fights than I am with this one with Anderson. Usually, there is more pressure like, 'I have to win. I have to keep this win streak alive. Then I can call out the big names, I can set myself up for a big fight.' There's a lot of pressure in the UFC to win so you can keep moving forward to bigger things. But, this is different. I cut out all that stuff. There is no pressure because it doesn't get any bigger than Anderson Silva and I've got nothing to lose. I'm a huge underdog, I'm fighting in his backyard. It's great ... all I've got to do is give him hell.

Thomas Myers (MMAmania.com): Do you, seriously, have a realistic chance of pulling off the biggest upset ever in a UFC main event and winning against literally ALL odds in Rio?

Stephan Bonnar: Yeah, I wouldn't get in there if I didn't think I could win this fight. Winning this fight changes my life, man. I'm going to give it everything I've got.