Conor McGregor will mark his return to the octagon after over a year away when he stands up opposite former UFC interim lightweight champion Dustin Poirier in the main event of UFC 257.Both the fighters are competing for a potential title shot in the future, and a hefty fight purse.According to Forbes, McGregor, inarguably the wealthiest fighter in the UFC, is set to pocket a minimum of $20 million. 'The Notorious' reportedly earned more than $30 million from his fight against Donald 'Cowboy' Cerrone at UFC 246 in January last year.Conor McGregor's listed purse for his rematch against Poirier is estimated to be at $5 million, however, taking the 32-year-old's pay-per-view share into account, he is likely to make at least $20 million.Before his clash against Cowboy, McGregor had claimed that he would earn $80 million from the fight."They think I'm toast, Ariel, but I'm still the bread." 🍞@TheNotoriousMMA says he made $50 million for the Khabib fight and predicts an $80 million payday for #UFC246 (via @arielhelwani) pic.twitter.com/UjpLhbDBAC— ESPN MMA (@espnmma) January 13, 2020Conor McGregor is the 16th richest athlete in the worldIn May 2020, Conor McGregor was ranked 16th in Forbes' list of the world's richest athletes, making him the wealthiest MMA fighter today.Reportedly, his net worth is around $120 million, thanks to his lucrative endorsement deals with brands like Beats by Dre, Reebok, Burger King, and many more..@thenotoriousmma makes @Forbes highest paid athlete list 💰https://t.co/6xByiNQwgT pic.twitter.com/Zuu5Q4NvV5— UFC (@ufc) June 15, 2016Conor McGregor's whiskey brand, Proper 12, his media company, The Mac Life, and clothing brand, August McGregor, also contribute plenty in the share of his hefty income.With the former UFC double champ likely to bag at least $20 million for fighting Dustin Poirier, the Irishman will return home after a mammoth payday.Ahead of the bout, Conor McGregor had predicted that he would knockout Poirier in less than 60 seconds, but wouldn't mind if the fight ends up going the distance.