UFC lightweight champion Nurmagomedov (27-0) who beat McGregor at UFC 229 in October in Las Vegas, will return to the Octagon in Abu Dhabi after a world wide victory tour.
The 30-year-old Russian from Dagestan was fined and banned for nine months for a brawl following his win over the Irishman, when he jumped outside the cage to attack McGregor’s coaching team, causing a riot.
Poirier, 30, who holds the interim title after beating fellow American Max Holloway in April. The championship fight will take place on Saturday, 7 September at Yas Island, in a purpose built outdoor venue, built especially for UFC 242.
Nurmagomedov initially claimed the lightweight title in April 2018 with a unanimous decision victory over Al Iaquinta, who was a last minute replacement.
He retained that title in October against McGregor, after a fiery build up, which Dana White declared as the ‘darkest press conference’ in UFC’s history.
McGregor was suspended for six months and fined $50,000 (£38,095) by the Nevada State Athletic Commission for his part, while Nurmagomedov was banned for nine months and fined $500,000 (£380,950).