UFC 230’s matchup between Dustin Poirier and Nate Diaz appears to be an obvious title eliminator for the lightweight division. Poirier is riding a streak of highlight-reel stoppage wins, while Diaz, despite his two-year layoff, remains the second-biggest star in the weight class at a time when the UFC’s lusting for star power is the greatest its ever been.

It’d be easy to assume the winner of Poirier vs. Diaz will earn the right to challenge the winner of UFC 229’s blockbuster title fight between lightweight champion Khabib Nurmagomedov and returning superstar Conor McGregor. But another option could exist out there as well. On Monday, former UFC welterweight and middleweight champion Georges St-Pierre told Submission Radio that he would be interested in cutting the line at lightweight and challenging the winner of Nurmagomedov vs. McGregor for the chance to become the first fighter in UFC history to earn belts in three different divisions.

St-Pierre has never competed at lightweight, but indicated that he feels confident he could make the cut down to 155 pounds if need be.

And to put things bluntly, Poirier is not a fan of the idea.

“Nah, it’s not happening,” Poirier said Monday on The MMA Hour.

“Look, after I beat Nate Diaz, I’m fighting for the belt. Or I’m fighting GSP, but he’s not going to get [a title shot] before I do.”

Poirier, 29, announced his arrival to title contention last month with a vicious second-round knockout of Eddie Alvarez at UFC on FOX 30. “The Diamond” is 8-1 since returning to the lightweight division — a run that includes notable stoppage wins over Justin Gaethje, Anthony Pettis, and Yancy Medeiros, among many others. After the Alvarez win, Poirier made it clear that he either wanted a title shot or a big fight next. His Nov. 3 meeting with Diaz certainly qualifies as the latter, although Poirier admitted Monday that he has not been guaranteed a title shot by the UFC with a win.

St-Pierre, on the other hand, is one of the biggest draws in MMA history and has long been rumored to be interested in a potential meeting against either McGregor or Nurmagomedov. “GSP” vacated his 185-pound strap last year after making history by returning from a four-year layoff and capturing the middleweight title with a win over Michael Bisping at UFC 217. He has since insisted that he only wants to come back for the type of legacy-defining fight that can boost his stock among the all-time greats. Taking on the winner of Nurmagomedov vs. McGregor could certainly do that.

“I would be interested in that fight,” St-Pierre said. “That’s a win-win situation. It’s a legacy upgrade and it’s good money — it’s gonna be a big fight. Yeah. However, I fought at 170, I relinquished a title. I fought at 185, I relinquished a title. I don’t think UFC will let me fight for the title at 155. They will be afraid I relinquish and I left the division in ruins.

“From my perspective, it’s a very winning situation. For UFC, it’s a big risk for them. Like I said, I’m older. I know Khabib, I’ve met Khabib many times. Khabib is actually bigger than me. He’s a bigger guy.”

Poirier isn’t hearing it, though.

After grinding for years to reach the point of legitimate title contention in the shark tank that is 155 pounds, “The Diamond” believes that his time has finally come. So when asked about St-Pierre’s proposal, Poirier’s stance was clear: “We’ll see about that.”

“When I beat Nate Diaz and it’s my turn to fight for that belt, when I win that belt, when history looks back at all of this, nobody can ever say I didn’t earn anything,” Poirier said. “I never took the easy route. I’ve always fought the best guys. I’ve never pulled out of a fight. I’ve never missed weight. I’ve put it all on the line every time, win, lose, or draw, and that’s what I want to be left behind in my legacy. A guy who just pushed through it all and kept at it and stayed true to the path, and this is all part of my legacy.”