The first of those routes is a ‘rubber match’ between Lesnar and Cain Velasquez. Velasquez made his WWE debut at Crown Jewel in October by losing to Lesnar in pretty quick fashion.
Of course that sort of puts them at 1-1 as Velasquez had previously beaten Lesnar for the UFC Heavyweight Championship, so ‘Mania would be the ultimate decider.
The other option is a bit similar in that pro-boxer Tyson Fury could be the man that faces Brock Lesnar on the grandest stage of them all.
Fury made his WWE debut at Crown Jewel too, but unlike Velasquez isn’t signed to a deal. He has been open about the fact he could very well return in the future, and if he did, he’d want it to be against Lesnar.
One of the factors this would depend on, however, is whether Fury can beat Deontay Wilder in their fight to become the WBC Heavyweight Champion, with the idea that having a boxing world champ against Lesnar is one that would appeal immensely to Vince McMahon.