It’s MMA’s longest-running mystery: When will the Diaz brothers fight next?

One big clue came down recently, as news broke that Nate Diaz is looking to end his two-year hiatus and potentially fight at UFC 227 in Los Angeles on Aug. 4.

Then there’s the other half of Stockton’s most famous brother combination, Nick Diaz. The older Diaz hasn’t fought in more than three years, in large part due to a much-ridiculed Nevada Athletic Commission marijuana suspension which many felt was over-the-top.

Will Nick Diaz, who is 34, ever compete in a mixed martial arts fight again? His longtime Skrap Pack running mate, Jake Shields, thinks that Diaz will return to the cage.

“I think he will I think he’ll fight again soon,” Shields said on a recent edition of The MMA Hour. “I think he’s mentioned it in training a little bit. I haven’t been out there so I don’t know how much he’s been training but I’m pretty sure he’s been in the gym a decent amount and I would love to see him fight again. I think he’s still got some more in him. He hasn’t been training as much but he’s still in good shape and he can come back fast.”

But Diaz is one of the sport’s most unpredictable personalities, and Shields concedes that even Diaz’s closest associates don’t always know what is going through one of MMA’s most enigmatic minds.

“Nick is a hard person to predict,” Shields said. “Only Nick really knows what he is going to do. People always ask ‘is Nick going to show up at a press conference?’ I’m like, ‘man, I can’t even tell you.’ Nic doesn’t even tell the people close to him, sometimes. He just kind of goes out and surprises everyone. Only Nick knows what he is going to do. If I had to guess I’d say he’ll fight again.

As coincidence has it, Shields has spent time training recently with one of Diaz’s most famous rivals: Georges St-Pierre.

Shields himself also fought GSP, in the main event of the legendary UFC 129 at Toronto’s Rogers Centre, which occurred seven years ago this week. But since moving to New York City last year, Shields has come to work with GSP through mutual coach John Danaher.

“It was really cool training with GSP,” Shields said. “I think the first time we trained together, it was kind of, there was a snowstorm that day, so it was only me, GSP, John and then another guy showed up. So it was really just training with him for the full hour. It was really cool, training with your former opponents and trying to help each other. I helped him a little bit training for [his fight with Michael] Bisping.”

Diaz might not exactly be enthused GSP is training with Shields, but Shields says he’s professional about it. And besides, should there ever come a time when Diaz and GSP rematch, Shields’ true loyalty lies with Team Cesar Gracie.

“It’s one of those things,” Shields said. “It’s obviously, Nick’s not thrilled about it, but he understands. I don’t think they’ll fight again at this point, but if for some reason they were, obviously I wouldn’t train with GSP. But it’s one of those things that, just, they understand it’s a sport, I’m here training with John and GSP trains with him so that’s kind of how it ended up.”