It’s been less than a week since Conor McGregor faced Floyd Mayweather in the boxing ring, but the mixed martial artist already has another challenger lined up to battle him in a meeting of world-class athleticism. And this time, the popular Irish fighter is being asked to step outside the ring.
Swimmer Michael Phelps, the world’s most decorated Olympian, just threw down the gauntlet on Twitter, extending a challenge to McGregor.
“All of this talk… should we race as well?” Phelps asked on Twitter.
McGregor stepped outside of his lane to compete against Mayweather over the weekend in the much-hyped boxing match. McGregor had never boxed professionally before, focusing on his career with the UFC. Meanwhile, Phelps himself has recently had some unconventional competitors in the water: he took to the open ocean this summer to race a (simulated) shark.
The Internet is, of course, intrigued by this unexpected potential match-up. With ringside seats for the Mayweather-McGregor match running a hefty $10,000 a pop, many are also seeing the dollar signs for both athletes if they should choose to move forward with the stunt set-up.
McGregor, for his part, has not yet responded to Phelps’ challenge.
More Must-Reads from TIME
- Donald Trump Is TIME's 2024 Person of the Year
- Why We Chose Trump as Person of the Year
- Is Intermittent Fasting Good or Bad for You?
- The 100 Must-Read Books of 2024
- The 20 Best Christmas TV Episodes
- Column: If Optimism Feels Ridiculous Now, Try Hope
- The Future of Climate Action Is Trade Policy
- Merle Bombardieri Is Helping People Make the Baby Decision
Write to Raisa Bruner at raisa.bruner@time.com