Gaethje, 33, was the UFC interim lightweight champion . He has a professional record of 23-3 and a UFC record of 6-3, including five victories in his previous six fights.
Charles Oliveira was stripped of his UFC title as he couldn't make the weight category.
"How many bridges do you burn before you look yourself in the mirror and say “maybe it’s me that’s the issue.”
Diaz (20-13 MMA) hasn't fought since UFC 263, when he lost a welterweight fight against Leon Edwards via unanimous decision.
Current UFC lightweight champion Charles Oliveria believes he can knock out both Dustin Poirier and Conor McGregor with ease.
Charles Oliveira became the 11th UFC lightweight champion after beating Michael Chandler in the main event of UFC 262.
The Ultimate Fighting Championship (UFC) returned with their latest pay-per-view offering UFC 262 on Sunday (May 16).
Oliveira was rocked and bloodied in Round 1, but survived to stop Chandler and claim the lightweight title in Round 2.
Michael Chandler will face Charles Oliveira for the vacant lightweight championship in UFC 262, and he predicts another first round KO win for himself.