Velasquez, 39, hasn’t fought since his knockout loss to Francis Ngannou over three years ago.
The American left for WWE in October 2019 but was released from his contract as a result of budget cuts due to the coronavirus pandemic.
Despite the setbacks, the MMA legend has kept himself in reasonable shape training alongside Islam Makhachev and Umar Nurmagomedov at American Kickboxing Academy, and Mendez has suggested a return for Velasquez could be on the cards.
“I don’t speak with him about those things. But it’s possible. If someone says, ‘Hey, here’s $2 million, let’s go fight,’ he might say, ‘Eh give me $4 [million] and I’ll do it.’
“I don’t know, but who knows – money talks most of the time. If the money is good and the UFC lets him, it’s possible that he may do it.
“But look, he’d have to fight in the UFC because even if you retire, you’re with the UFC.
“The UFC needs to give you permission, and if they don’t, you can’t do anything.
“He is doing pro wrestling, but that’s different. You can’t box, you can’t fight. If he wants to fight, the UFC needs to give him permission.”
After his defeat to Ngannou in February 2019, the 39-year-old ex-heavyweight champion of the world announced his retirement from mixed martial arts, citing lingering issues that required treatment.
He added: “He does have more [in the tank] than what Daniel had. He’s not the same. Cain is not the same as when he was younger, but he does have more left than Daniel.
“He is younger – he’s not in his 40s. Remember, Daniel was 42 and he had a back surgery, and after the surgery DC wasn’t the same. The years caught up to him.
“All the wear and tear and everything came to an end with him. In his mind, he was always a champion. With Daniel, his mind was always stronger than his body.”