UFC welterweight Nick Diaz, one of the most popular fighters in MMA history, could be back in the Octagon as soon as next month. Diaz accepted a one-year suspension from the United States Anti-Doping Agency (USADA) on Monday for missing three out-of-competition drug tests within a 12-month span. The one-year period of ineligibility is retroactive to the date of Diaz's third missed test, which was April 19, 2017, meaning the suspension ends in just 10 days.

He has not fought since January 2015.

If he chooses to compete again, who should he fight? We asked our panel -- ESPN MMA reporter Brett Okamoto, ESPN MMA editor Greg Rosenstein, SportsCenter host Phil Murphy and digital contributor Jeff Wagenheim -- for their takes.

Okamoto: Georges St-Pierre

Definitely NOT Conor McGregor. Don't even say it. The answer to every, "Who should (insert name) fight next?" can't always be McGregor. That's just lazy. And in this case, it's just wrong. McGregor's original rival is Nate, and that's one of the best rivalries ever. Don't mess with it.

My top opponent for Diaz, assuming he actually does want to fight, would be his original rival: Georges St-Pierre.

You want to talk about another one of the greatest rivalries of all time -- look no further than GSP, Diaz. When they fought in 2013, it wasn't great. And I can't guarantee it would be great five years later. But this sport loves to revisit the past, and this would be a fun reboot.

Rosenstein: Robbie Lawler

Nick Diaz being back in MMA -- if he actually decides to compete -- is good for everyone involved. He's one of the most popular fighters in history for a reason. Fans know they'll get what they pay for both in and outside the Octagon. As far as his first matchup, I'm hoping he'll take on Robbie Lawler in a rematch from UFC 27 in 2004.

Unlike his fight against GSP, this was a back-and-forth battle I would love to see again. There's close to a zero percent chance this matchup wouldn't produce fireworks. Lawler, at 36, is in the back half of his career and has lost two of three. A marquee fight against a big name who hasn't competed in three years makes sense. He likely wants to avenge this loss, and fans no doubt hope to see it.

Nick Diaz lost to Georges St-Pierre by unanimous decision at UFC 158 in March 2013. Ross Dettman for ESPN.com

Murphy: Georges St-Pierre

Bring on the wolf tickets.

Nick Diaz isn't a serious title contender, nor will he ever be again. He hasn't won a fight in more than six years. Any matchups with any bearing on, say, the welterweight hierarchy should be thrown out.

Diaz's return needs a fun backstory, something to grab casual fans' interest aside from what it would mean for a belt. Enter the man against whom Diaz claimed he was drugged when they met at UFC 158: Georges St-Pierre.

GSP isn't rushing into his next bout -- pun fully intended. He wants high payday with low risk. The elder Diaz presents just that.

And it gives us all a chance to relive this gem over and over until the cage door shuts on their likely pay-per-view co-main event.

Wagenheim: Michael Bisping

The real answer: everyone. Try to name a Nick Diaz matchup that doesn't make your heart go thump.

Actually, there is one, so let's tweak the answer to "anyone but Floyd Mayweather," because Diaz doesn't need a circus to perform his human cannonball act. And since we're doing subtraction, I'll discard one more name from the hat: Tyron Woodley. No way Diaz -- idle for over three years, winless in six-and-a-half years -- is deserving of a shot at the welterweight title.

Anyone else, bring him on. Wouldn't you love to see Diaz and Robbie Lawler put on an encore 14 years later? Imagine a McGregor-Diaz III that pitted Conor against a different representative of the First Family of 209. What if Georges St-Pierre grabbed a mic and implored, "Où tu es, Nick?"

But I'm not hearing French in my matchmaking mind, I'm hearing "Don't be scared, homie" in a Lancashire accent. Michael Bisping is as relentlessly forward-moving as Diaz, and no less surly. And because he is on his way out of the fight game, Bisping would leave everything he has left in the Octagon.