St-Pierre, who UFC President Dana White said asked for the matchup, said his logic is simple. He believes a fight with Diaz is the matchup fans want to see.
"This fight has been waiting to happen for a long time," St-Pierre said. "It's the big fight. That's what people want to see.
"Everybody wants to fight me now. It's crazy. I cannot split myself in half. If I would have not have done that, I would do another fight, and fans would have complained. If I fight another guy, they both would have complained. What do you want me to do? I cannot split myself in different pieces and fight guys all at the same time."
St-Pierre and Diaz were, of course, supposed to fight in 2011 before the challenger was pulled from the matchup for infamously failing to handle his pre-fight obligations. Diaz would eventually go on to lose to Carlos Condit and suffer a yearlong suspension from the Nevada State Athletic Commission after failing a post-fight drug screen.
Meanwhile, Hendricks is riding a five-fight win streak that includes victories over top contenders Jon Fitch, Josh Koscheck and Martin Kampmann, among others.
Still, St-Pierre insists he believes Diaz is the rightful No. 1 contender based on his career accomplishments and the face that "Rush" thinks Hendricks actually lost a razor-thin decision to Koscheck.
"I believe Diaz is No. 1 ranked," St-Pierre told MMAjunkie.com (www.mmajunkie.com). "The guy has been there for a long time. He took out a great name (in B.J. Penn). His fight with Condit is very controversial. For some people, he won the fight. For some people, he lost.
"Hendricks, when he fought Koscheck, personally I would have given the fight to Koscheck. … I speak with my heart, and that's what I believe. I would have given Koscheck that fight, even though I don't like Koscheck."
Which led St-Pierre to Diaz. He still thinks Hendricks is likely next should he earn a win over Jake Ellenberger in another big fight on the UFC 158 card. He also knows Silva is lurking in the background, but St-Pierre thinks he'll need time to pack on the muscle necessary to compete with the world's best 185-pounder.
After a lengthy time away from the sport to recover from injury, St-Pierre said he simply doesn't want to take that kind of break right now. He's itching to fight, and Diaz provides the perfect opportunity.
"I do feel bad for Johny Hendricks, but put yourself in my shoes," St-Pierre. "[Diaz] is a big fight. For me, right now, it's the fight that makes the most sense. If I fight Anderson Silva, I have to go up in weight. It will take me time. I cannot fight Anderson in March. It would take time. So right now, I take the fight that is the most logical.
"I just came back from 19 months. It's a long time, and the fight that people wanted to see that I can give it to them fast and when it's time to do it is Diaz. … So it's a big fight that people want to see me in, Diaz and I, so I want to make this fight happen for myself, for the fans and for the UFC."Link